Update webpack-dev-middleware to 0.17.4 (#827)

Author: EladBezalel

package.json

@@ -13,7 +13,7 @@
     "connect-history-api-fallback": "^1.3.0",
     "express": "^4.13.3",
     "html-entities": "^1.2.0",
-    "http-proxy-middleware": "~0.17.1",
+    "http-proxy-middleware": "~0.17.4",
     "opn": "4.0.2",
     "portfinder": "^1.0.9",
     "serve-index": "^1.7.2",