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

Closes #18

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
   "devDependencies": {
     "babel-cli": "^6.24.1",
     "babel-core": "^6.25.0",
-    "babel-loader": "^7.1.1",
+    "babel-loader": "^8.0.4",
     "babel-plugin-transform-es2015-modules-commonjs": "^6.24.1",
     "babel-plugin-transform-es2015-modules-umd": "^6.24.1",
     "babel-plugin-transform-object-assign": "^6.22.0",