Upgrade optimize-css-assets-webpack-plugin and css-loader

Author: ArayB

package.json

@@ -104,7 +104,7 @@
     "mocha": "^3.2.0",
     "nodemon": "^1.17.5",
     "opn": "^4.0.2",
-    "optimize-css-assets-webpack-plugin": "^1.3.0",
+    "optimize-css-assets-webpack-plugin": "^2.0.0",
     "ora": "^1.2.0",
     "phantomjs-prebuilt": "^2.1.14",
     "po-loader": "^0.4.1",