Merge tag 'v2.2.0' of github.com:OpenZeppelin/openzeppelin-solidity

v2.2.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "openzeppelin-eth",
-  "version": "2.1.3",
+  "version": "2.2.0",
   "description": "Secure Smart Contract library for Solidity",
   "files": [
     "build",
@@ -58,7 +58,7 @@
     "openzeppelin-test-helpers": "^0.1.1",
     "pify": "^4.0.1",
     "solhint": "^1.5.0",
-    "solidity-coverage": "^0.5.4",
+    "solidity-coverage": "https://github.com:rotcivegaf/solidity-coverage.git#5875f5b7bc74d447f3312c9c0e9fc7814b482477",
     "truffle": "^5.0.0",
     "zos": "^2.0.0",
     "zos-lib": "^2.1.0"