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

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "css-loader": "^1.0.1",
     "eslint": "^6.3.0",
     "jest": "^24.9.0",
-    "mini-css-extract-plugin": "^0.8.0",
+    "mini-css-extract-plugin": "^0.9.0",
     "prettier": "^1.18.2",
     "rollup": "^1.21.2",
     "rollup-plugin-babel": "^4.3.3",