fix(package): update babel-loader to version 8.0.4

Closes #229

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
     "@sendgrid/mail": "^6.1.4",
     "babel-core": "^6.26.0",
     "babel-eslint": "^8.2.1",
-    "babel-loader": "^7.1.2",
+    "babel-loader": "^8.0.4",
     "babel-plugin-syntax-dynamic-import": "^6.18.0",
     "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-env": "^1.6.0",