Merge pull request #8 from jedwards1211/greenkeeper/babel-plugin-istanbul-4.0.0

Update babel-plugin-istanbul to the latest version 🚀

Author: jedwards1211

package.json

@@ -61,7 +61,7 @@
     "babel-core": "^6.21.0",
     "babel-eslint": "^7.1.1",
     "babel-plugin-flow-react-proptypes": "^0.21.0",
-    "babel-plugin-istanbul": "^3.1.2",
+    "babel-plugin-istanbul": "^4.0.0",
     "babel-plugin-transform-react-constant-elements": "^6.9.1",
     "babel-plugin-transform-runtime": "^6.15.0",
     "babel-preset-es2015": "^6.18.0",