Merge pull request #255 from textpattern/greenkeeper/sass-1.23.1

Update sass to the latest version 🚀

Author: philwareham

package.json

@@ -26,7 +26,7 @@
     "grunt-sass": "3.1.0",
     "grunt-sass-lint": "0.2.4",
     "load-grunt-tasks": "5.1.0",
-    "sass": "1.23.0",
+    "sass": "1.23.1",
     "sass-lint": "1.13.1"
   },
   "dependencies": {