chore(package): update stylelint-config-standard to version 20.0.0

Closes #145

Author: greenkeeper[bot]

package.json

@@ -109,7 +109,7 @@
     "spectron": "^4.0.0",
     "style-loader": "^0.23.0",
     "stylelint": "^9.1.1",
-    "stylelint-config-standard": "^18.0.0",
+    "stylelint-config-standard": "^20.0.0",
     "ts-jest": "^22.4.0",
     "ts-node": "^6.0.0",
     "tslib": "^1.7.1",