Merge pull request #22 from edx/greenkeeper/eslint-config-edx-4.0.0

Update eslint-config-edx to the latest version 🚀

package.json

@@ -44,7 +44,7 @@
     "enzyme": "^2.8.2",
     "eslint": "^3.19.0",
     "eslint-config-airbnb": "^15.0.1",
-    "eslint-config-edx": "^3.0.0",
+    "eslint-config-edx": "^4.0.0",
     "eslint-import-resolver-webpack": "^0.8.1",
     "eslint-plugin-jsx-a11y": "^5.1.0",
     "eslint-plugin-react": "^7.1.0",