Bump package version for Truffle, Solhint & Solidty Coverage.

contracts/eip20/EIP20.sol

@@ -3,7 +3,7 @@ Implements EIP20 token standard: https://github.com/ethereum/EIPs/blob/master/EI
 .*/
 
 
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.21;
 
 import "./EIP20Interface.sol";
 

package.json

@@ -34,7 +34,7 @@
   },
   "homepage": "https://github.com/ConsenSys/Tokens#readme",
   "dependencies": {
-    "truffle": "4.0.6",
+    "truffle": "4.1.5",
     "truffle-hdwallet-provider": "0.0.3"
   },
   "devDependencies": {
@@ -46,7 +46,7 @@
     "eslint-plugin-mocha": "4.11.0",
     "eslint-plugin-node": "5.1.0",
     "eslint-plugin-react": "7.5.1",
-    "solhint": "1.1.9",
-    "solidity-coverage": "0.4.9"
+    "solhint": "1.1.10",
+    "solidity-coverage": "0.4.15"
   }
 }