Add babel eslint plugin

As our linter has been failing because it needs it

Author: dbkr

package.json

@@ -104,6 +104,7 @@
     "emojione": "^2.2.7",
     "eslint": "^3.14.0",
     "eslint-config-google": "^0.7.1",
+    "eslint-plugin-babel": "^4.1.1",
     "eslint-plugin-flowtype": "^2.30.0",
     "eslint-plugin-react": "^6.9.0",
     "expect": "^1.16.0",