chore(package): update eslint-plugin-standard to version 2.1.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -67,7 +67,7 @@
     "eslint-config-semistandard": "7.0.0",
     "eslint-config-standard": "6.1.0",
     "eslint-plugin-promise": "^3.4.1",
-    "eslint-plugin-standard": "2.0.1",
+    "eslint-plugin-standard": "2.1.1",
     "gulp": "3.9.1",
     "gulp-add-src": "0.2.0",
     "gulp-clean-css": "^3.0.2",