Merge branch 'master' of github.com:OpenZeppelin/openzeppelin-contracts into gsn-beta

contracts/crowdsale/Crowdsale.sol

@@ -138,6 +138,7 @@ contract Crowdsale is ReentrancyGuard {
     function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
         require(beneficiary != address(0), "Crowdsale: beneficiary is the zero address");
         require(weiAmount != 0, "Crowdsale: weiAmount is 0");
+        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
     }
 
     /**

contracts/utils/ReentrancyGuard.sol

@@ -4,7 +4,7 @@ pragma solidity ^0.5.0;
  * @dev Contract module that helps prevent reentrant calls to a function.
  *
  * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
- * available, which can be aplied to functions to make sure there are no nested
+ * available, which can be applied to functions to make sure there are no nested
  * (reentrant) calls to them.
  *
  * Note that because there is a single `nonReentrant` guard, functions marked as

scripts/coverage.sh

@@ -3,5 +3,5 @@
 SOLIDITY_COVERAGE=true scripts/test.sh
 
 if [ "$CI" = true ]; then
-  curl -s https://codecov.io/bash | bash -s
+  curl -s https://codecov.io/bash | bash -s -- -C "$CIRCLE_SHA1"
 fi