chore(package): update stylelint to version 13.5.0

Closes #81

Author: greenkeeper[bot]

package.json

@@ -25,6 +25,6 @@
     "less": "^3.8.0",
     "less-plugin-autoprefix": "^1.5.1",
     "less-plugin-clean-css": "^1.5.1",
-    "stylelint": "^9.3.0"
+    "stylelint": "^13.5.0"
   }
 }