Replaced assert with require

test/helpers/ReentrancyAttack.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.4.11;
 contract ReentrancyAttack {
 
   function callSender(bytes4 data) {
-    assert(msg.sender.call(data));
+    require(msg.sender.call(data));
   }
 
 }

test/helpers/ReentrancyMock.sol

@@ -27,7 +27,7 @@ contract ReentrancyMock is ReentrancyGuard {
     if(n > 0) {
       count();
       bool result = this.call(func, n - 1);
-      assert(result == true);
+      require(result == true);
     }
   }