Added gaps at the end of the storage of each contract.

contracts/Initializable.sol

@@ -46,4 +46,6 @@ contract Initializable {
     assembly { cs := extcodesize(address) }
     return cs == 0;
   }
+
+  uint256[50] private ______gap;
 }

contracts/access/roles/CapperRole.sol

@@ -44,4 +44,6 @@ contract CapperRole is Initializable {
     cappers.remove(account);
     emit CapperRemoved(account);
   }
+
+  uint256[50] private ______gap;
 }

contracts/access/roles/MinterRole.sol

@@ -44,4 +44,6 @@ contract MinterRole is Initializable {
     minters.remove(account);
     emit MinterRemoved(account);
   }
+
+  uint256[50] private ______gap;
 }

contracts/access/roles/PauserRole.sol

@@ -44,4 +44,6 @@ contract PauserRole is Initializable {
     pausers.remove(account);
     emit PauserRemoved(account);
   }
+
+  uint256[50] private ______gap;
 }

contracts/access/roles/SignerRole.sol

@@ -44,4 +44,6 @@ contract SignerRole is Initializable {
     signers.remove(account);
     emit SignerRemoved(account);
   }
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/Crowdsale.sol

@@ -232,4 +232,6 @@ contract Crowdsale is Initializable {
   function _forwardFunds() internal {
     _wallet.transfer(msg.value);
   }
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/distribution/FinalizableCrowdsale.sol

@@ -46,4 +46,6 @@ contract FinalizableCrowdsale is Initializable, TimedCrowdsale {
   function _finalization() internal {
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/distribution/PostDeliveryCrowdsale.sol

@@ -48,4 +48,6 @@ contract PostDeliveryCrowdsale is Initializable, TimedCrowdsale {
     _balances[beneficiary] = _balances[beneficiary].add(tokenAmount);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/distribution/RefundableCrowdsale.sol

@@ -84,4 +84,6 @@ contract RefundableCrowdsale is Initializable, FinalizableCrowdsale {
     _escrow.deposit.value(msg.value)(msg.sender);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/emission/AllowanceCrowdsale.sol

@@ -54,4 +54,6 @@ contract AllowanceCrowdsale is Initializable, Crowdsale {
   {
     token().safeTransferFrom(_tokenWallet, beneficiary, tokenAmount);
   }
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/emission/MintedCrowdsale.sol

@@ -27,4 +27,6 @@ contract MintedCrowdsale is Initializable, Crowdsale {
     require(
       ERC20Mintable(address(token())).mint(beneficiary, tokenAmount));
   }
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/price/IncreasingPriceCrowdsale.sol

@@ -68,4 +68,6 @@ contract IncreasingPriceCrowdsale is Initializable, TimedCrowdsale {
     return currentRate.mul(weiAmount);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/validation/CappedCrowdsale.sol

@@ -53,4 +53,6 @@ contract CappedCrowdsale is Initializable, Crowdsale {
     require(weiRaised().add(weiAmount) <= _cap);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/validation/IndividuallyCappedCrowdsale.sol

@@ -81,4 +81,6 @@ contract IndividuallyCappedCrowdsale is Initializable, Crowdsale, CapperRole {
       weiAmount);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/crowdsale/validation/TimedCrowdsale.sol

@@ -83,4 +83,6 @@ contract TimedCrowdsale is Initializable, Crowdsale {
     super._preValidatePurchase(beneficiary, weiAmount);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/drafts/BreakInvariantBounty.sol

@@ -75,6 +75,8 @@ contract BreakInvariantBounty is Initializable, PullPayment, Ownable {
    */
   function _deployContract() internal returns(address);
 
+
+  uint256[50] private ______gap;
 }
 
 
@@ -91,4 +93,6 @@ contract Target {
     * @return True if all invariant values are correct, false otherwise.
     */
   function checkInvariant() public returns(bool);
+
+  uint256[50] private ______gap;
 }

contracts/drafts/ERC1046/TokenMetadata.sol

@@ -12,6 +12,8 @@ import "../../token/ERC20/IERC20.sol";
  */
 contract ERC20TokenMetadata is Initializable, IERC20 {
   function tokenURI() external view returns (string);
+
+  uint256[50] private ______gap;
 }
 
 
@@ -28,4 +30,6 @@ contract ERC20WithMetadata is Initializable, ERC20TokenMetadata {
   function tokenURI() external view returns (string) {
     return _tokenURI;
   }
+
+  uint256[50] private ______gap;
 }

contracts/drafts/ERC20Migrator.sol

@@ -99,4 +99,6 @@ contract ERC20Migrator is Initializable {
     uint256 amount = Math.min(balance, allowance);
     migrate(account, amount);
   }
+
+  uint256[50] private ______gap;
 }

contracts/drafts/SignatureBouncer.sol

@@ -140,4 +140,6 @@ contract SignatureBouncer is Initializable, SignerRole {
 
     return signer != address(0) && isSigner(signer);
   }
+
+  uint256[50] private ______gap;
 }

contracts/drafts/TokenVesting.sol

@@ -176,4 +176,6 @@ contract TokenVesting is Initializable, Ownable {
       return totalBalance.mul(block.timestamp.sub(_start)).div(_duration);
     }
   }
+
+  uint256[50] private ______gap;
 }

contracts/examples/SampleCrowdsale.sol

@@ -25,6 +25,8 @@ contract SampleCrowdsaleToken is Initializable, ERC20Mintable {
     symbol = "SCT";
     decimals = 18;
   }
+
+  uint256[50] private ______gap;
 }
 
 
@@ -67,4 +69,6 @@ contract SampleCrowdsale is Initializable, Crowdsale, CappedCrowdsale, Refundabl
     //the value needs to less or equal than a cap which is limit for accepted funds
     require(goal <= cap);
   }
+
+  uint256[50] private ______gap;
 }

contracts/examples/SimpleToken.sol

@@ -26,4 +26,6 @@ contract SimpleToken is Initializable, ERC20 {
     _mint(sender, INITIAL_SUPPLY);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/introspection/ERC165.sol

@@ -53,4 +53,6 @@ contract ERC165 is Initializable, IERC165 {
     require(interfaceId != 0xffffffff);
     _supportedInterfaces[interfaceId] = true;
   }
+
+  uint256[50] private ______gap;
 }

contracts/lifecycle/Pausable.sol

@@ -56,4 +56,6 @@ contract Pausable is Initializable, PauserRole {
     _paused = false;
     emit Unpaused();
   }
+
+  uint256[50] private ______gap;
 }

contracts/ownership/Ownable.sol

@@ -76,4 +76,6 @@ contract Ownable is Initializable {
     emit OwnershipTransferred(_owner, newOwner);
     _owner = newOwner;
   }
+
+  uint256[50] private ______gap;
 }

contracts/ownership/Secondary.sol

@@ -33,4 +33,6 @@ contract Secondary is Initializable {
 
     _primary = recipient;
   }
+
+  uint256[50] private ______gap;
 }

contracts/payment/ConditionalEscrow.sol

@@ -24,4 +24,6 @@ contract ConditionalEscrow is Initializable, Escrow {
     require(withdrawalAllowed(payee));
     super.withdraw(payee);
   }
+
+  uint256[50] private ______gap;
 }

contracts/payment/Escrow.sol

@@ -52,4 +52,6 @@ contract Escrow is Initializable, Secondary {
 
     emit Withdrawn(payee, payment);
   }
+
+  uint256[50] private ______gap;
 }

contracts/payment/PullPayment.sol

@@ -44,4 +44,6 @@ contract PullPayment is Initializable {
   function _asyncTransfer(address dest, uint256 amount) internal {
     _escrow.deposit.value(amount)(dest);
   }
+
+  uint256[50] private ______gap;
 }

contracts/payment/RefundEscrow.sol

@@ -87,4 +87,6 @@ contract RefundEscrow is Initializable, ConditionalEscrow {
   function withdrawalAllowed(address payee) public view returns (bool) {
     return _state == State.Refunding;
   }
+
+  uint256[50] private ______gap;
 }

contracts/payment/SplitPayment.sol

@@ -107,4 +107,6 @@ contract SplitPayment is Initializable {
     _shares[account] = shares_;
     _totalShares = _totalShares.add(shares_);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/ERC20.sol

@@ -210,4 +210,6 @@ contract ERC20 is Initializable, IERC20 {
       amount);
     _burn(account, amount);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/ERC20Burnable.sol

@@ -26,4 +26,6 @@ contract ERC20Burnable is Initializable, ERC20 {
   function burnFrom(address from, uint256 value) public {
     _burnFrom(from, value);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/ERC20Capped.sol

@@ -47,4 +47,6 @@ contract ERC20Capped is Initializable, ERC20Mintable {
     return super.mint(to, amount);
   }
 
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/ERC20Detailed.sol

@@ -41,4 +41,6 @@ contract ERC20Detailed is Initializable, IERC20 {
   function decimals() public view returns(uint8) {
     return _decimals;
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/ERC20Mintable.sol

@@ -31,4 +31,6 @@ contract ERC20Mintable is Initializable, ERC20, MinterRole {
     _mint(to, amount);
     return true;
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/ERC20Pausable.sol

@@ -70,4 +70,6 @@ contract ERC20Pausable is Initializable, ERC20, Pausable {
   {
     return super.decreaseAllowance(spender, subtractedValue);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC20/TokenTimelock.sol

@@ -69,4 +69,6 @@ contract TokenTimelock is Initializable {
 
     _token.safeTransfer(_beneficiary, amount);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721.sol

@@ -327,4 +327,6 @@ contract ERC721 is Initializable, ERC165, IERC721 {
       msg.sender, from, tokenId, _data);
     return (retval == _ERC721_RECEIVED);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Burnable.sol

@@ -15,4 +15,6 @@ contract ERC721Burnable is Initializable, ERC721 {
     require(_isApprovedOrOwner(msg.sender, tokenId));
     _burn(ownerOf(tokenId), tokenId);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Enumerable.sol

@@ -147,4 +147,6 @@ contract ERC721Enumerable is Initializable, ERC165, ERC721, IERC721Enumerable {
     _allTokensIndex[tokenId] = 0;
     _allTokensIndex[lastToken] = tokenIndex;
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Full.sol

@@ -21,4 +21,6 @@ contract ERC721Full is Initializable, ERC721, ERC721Enumerable, ERC721Metadata {
     ERC721Enumerable.initialize();
     ERC721Metadata.initialize(name, symbol);
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Holder.sol

@@ -16,4 +16,6 @@ contract ERC721Holder is Initializable, IERC721Receiver {
   {
     return this.onERC721Received.selector;
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Metadata.sol

@@ -89,4 +89,6 @@ contract ERC721Metadata is Initializable, ERC165, ERC721, IERC721Metadata {
       delete _tokenURIs[tokenId];
     }
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721MetadataMintable.sol

@@ -35,4 +35,6 @@ contract ERC721MetadataMintable is Initializable, ERC721, ERC721Metadata, Minter
     _setTokenURI(tokenId, tokenURI);
     return true;
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Mintable.sol

@@ -32,4 +32,6 @@ contract ERC721Mintable is Initializable, ERC721, MinterRole {
     _mint(to, tokenId);
     return true;
   }
+
+  uint256[50] private ______gap;
 }

contracts/token/ERC721/ERC721Pausable.sol

@@ -45,4 +45,6 @@ contract ERC721Pausable is Initializable, ERC721, Pausable {
   {
     super.transferFrom(from, to, tokenId);
   }
+
+  uint256[50] private ______gap;
 }

contracts/utils/Address.sol

@@ -25,5 +25,4 @@ library Address {
     assembly { size := extcodesize(account) }
     return size > 0;
   }
-
 }

contracts/utils/ReentrancyGuard.sol

@@ -32,4 +32,5 @@ contract ReentrancyGuard is Initializable {
     require(localCounter == _guardCounter);
   }
 
+  uint256[50] private ______gap;
 }