chore(package): update webpack-dev-middleware to version 3.1.3

Closes #6

Author: greenkeeper[bot]

package.json

@@ -58,7 +58,7 @@
     "vue-style-loader": "^4.0.2",
     "vue-template-compiler": "^2.5.3",
     "webpack": "^3.8.1",
-    "webpack-dev-middleware": "^2.0.5",
+    "webpack-dev-middleware": "^3.1.3",
     "webpack-hot-middleware": "^2.20.0",
     "webpack-merge": "^4.1.1",
     "webpack-node-externals": "^1.6.0"