chore(package): update dependencies

Author: greenkeeper[bot]

package.json

@@ -96,7 +96,7 @@
     "source-map-loader": "^0.2.3",
     "style-loader": "^0.20.3",
     "travis-deploy-once": "^4.4.1",
-    "webpack": "^3.10.0",
+    "webpack": "^4.5.0",
     "webpack-build-notifier": "^0.1.23",
     "webpack-cli": "^2.0.14",
     "webpack-dev-server": "^3.1.3"