Downgrade cssLoader because of bug 'Promise is not defined'

Author: Erik Peldan

package.json

@@ -42,7 +42,7 @@
     "babel-core": "^5.6.18",
     "babel-loader": "^5.1.4",
     "babel-plugin-react-transform": "^1.1.0",
-    "css-loader": "^0.21.0",
+    "css-loader": "0.18.0",
     "expect": "^1.6.0",
     "express": "^4.13.3",
     "mocha": "^2.3.3",