chore(package): update style-loader to version 0.20.0

Author: greenkeeper[bot]

package.json

@@ -60,7 +60,7 @@
     "remap-istanbul": "^0.10.0",
     "rimraf": "^2.6.2",
     "sass-loader": "^6.0.6",
-    "style-loader": "^0.19.1",
+    "style-loader": "^0.20.0",
     "tslint": "^5.8.0",
     "tslint-loader": "^3.5.3",
     "typescript": "^2.6.2",