chore(package): update babel-loader to version 6.4.1

Closes #1972

https://greenkeeper.io/

package.json

@@ -222,7 +222,7 @@
     "babel-core": "6.23.1",
     "babel-eslint": "7.1.0",
     "babel-gettext-extractor": "git+https://github.com/muffinresearch/babel-gettext-extractor.git#ecd85dea4553247a3cb579da817df29f381df5b9",
-    "babel-loader": "6.3.2",
+    "babel-loader": "6.4.1",
     "babel-plugin-istanbul": "4.0.0",
     "babel-plugin-react-transform": "2.0.2",
     "babel-plugin-transform-class-properties": "6.18.0",