chore(package): update css-loader to version 0.26.0 (#883)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -63,7 +63,7 @@
     "connect-history-api-fallback": "^1.2.0",
     "copy-to-clipboard": "^3.0.5",
     "cross-env": "^3.1.3",
-    "css-loader": "^0.25.0",
+    "css-loader": "^0.26.0",
     "del": "^2.2.2",
     "dirty-chai": "^1.2.2",
     "doctoc": "^1.2.0",