Fix merge errors

contracts/mocks/ClonesMock.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 
-pragma solidity >=0.6.0 <0.9.0;
+pragma solidity ^0.8.0;
 
 import "../proxy/Clones.sol";
 import "../utils/Address.sol";

contracts/proxy/Clones.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 
-pragma solidity >=0.6.0 <0.9.0;
+pragma solidity ^0.8.0;
 
 /**
  * @dev https://eips.ethereum.org/EIPS/eip-1167[EIP 1167] is a standard for

contracts/token/ERC20/ERC20Capped.sol

@@ -37,7 +37,7 @@ abstract contract ERC20Capped is ERC20 {
         super._beforeTokenTransfer(from, to, amount);
 
         if (from == address(0)) { // When minting tokens
-            require(totalSupply() + amount <= _cap, "ERC20Capped: cap exceeded");
+            require(totalSupply() + amount <= cap(), "ERC20Capped: cap exceeded");
         }
     }
 }

contracts/utils/Context.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 
-pragma solidity >=0.6.0 <0.9.0;
+pragma solidity ^0.8.0;
 
 /*
  * @dev Provides information about the current execution context, including the