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

Closes #131

Author: greenkeeper[bot]

package.json

@@ -76,7 +76,7 @@
     "react-test-renderer": "^16.7.0",
     "rimraf": "^2.6.3",
     "stylelint": "^9.9.0",
-    "stylelint-config-standard": "^18.2.0"
+    "stylelint-config-standard": "^20.0.0"
   },
   "engines": {
     "node": ">=6"