introduce webpack2 dependencies

Author: Foxandxss

package.json

@@ -47,7 +47,7 @@
     "raw-loader": "^0.5.1",
     "rimraf": "^2.5.1",
     "style-loader": "^0.13.0",
-    "webpack": "^1.12.2",
-    "webpack-dev-server": "^1.12.1"
+    "webpack": "^2.0.7-beta",
+    "webpack-dev-server": "^2.0.0-beta"
   }
 }