chore(package): update sass-lint to version 1.12.0

Author: greenkeeper[bot]

package.json

@@ -31,7 +31,7 @@
     "grunt-sass-lint": "0.2.3",
     "load-grunt-tasks": "~3.5",
     "node-sass": "4.5.3",
-    "sass-lint": "1.11.1"
+    "sass-lint": "1.12.0"
   },
   "browserslist": [
     "last 2 versions",