chore(package): update webpack to version 3.8.0

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
     "nyc": "11.2.1",
     "standard-version": "4.2.0",
     "text-loader": "0.0.1",
-    "webpack": "3.7.0",
+    "webpack": "3.8.0",
     "xo": "0.18.2"
   }
 }