chore(package): update mini-css-extract-plugin to version 0.9.0

Closes #82

Author: greenkeeper[bot]

package.json

@@ -90,7 +90,7 @@
     "jest": "^22.4.3",
     "jest-css-modules": "^1.1.0",
     "jest-fetch-mock": "^1.5.0",
-    "mini-css-extract-plugin": "^0.4.0",
+    "mini-css-extract-plugin": "^0.9.0",
     "prop-types": "^15.6.1",
     "query-string": "^6.0.0",
     "react": "^16.3.0",