Merge pull request #4 from jedwards1211/greenkeeper/babel-plugin-istanbul-4.0.0

Update babel-plugin-istanbul to the latest version 🚀

Author: jedwards1211

package.json

@@ -55,7 +55,7 @@
     "babel-cli": "^6.22.2",
     "babel-core": "^6.22.1",
     "babel-eslint": "^7.1.1",
-    "babel-plugin-istanbul": "^3.1.2",
+    "babel-plugin-istanbul": "^4.0.0",
     "babel-plugin-transform-runtime": "^6.22.0",
     "babel-preset-es2015": "^6.22.0",
     "babel-preset-flow": "^1.0.0",