Update dependencies

package.json

@@ -61,8 +61,7 @@
     "eslint-plugin-node": "^10.0.0",
     "eslint-plugin-promise": "^4.2.1",
     "eslint-plugin-standard": "^4.0.1",
-    "ethereumjs-util": "^7.0.1",
-    "ganache-core-coverage": "https://github.com/OpenZeppelin/ganache-core-coverage/releases/download/2.5.3-coverage/ganache-core-coverage-2.5.3.tgz",
+    "ethereumjs-util": "^7.0.7",
     "lodash.startcase": "^4.4.0",
     "lodash.zip": "^4.2.0",
     "micromatch": "^4.0.2",