chore(package): update babel-loader to version 8.0.5

Closes #258

package.json

@@ -29,9 +29,9 @@
     "@babel/register": "^7.0.0",
     "ava": "^1.1.0",
     "babel-cli": "^6.26.0",
-    "babel-core": "^6.26.3",
+    "babel-core": "^7.2.2",
     "babel-eslint": "^10.0.1",
-    "babel-loader": "^7.1.5",
+    "babel-loader": "^8.0.5",
     "babel-plugin-add-module-exports": "^1.0.0",
     "babel-plugin-istanbul": "^4.1.6",
     "babel-polyfill": "^6.26.0",