Merge pull request #270 from textpattern/greenkeeper/sass-1.24.4

chore(package): update sass to version 1.24.4

Author: philwareham

package.json

@@ -25,7 +25,7 @@
     "grunt-sass": "3.1.0",
     "grunt-stylelint": "0.13.0",
     "load-grunt-tasks": "5.1.0",
-    "sass": "1.24.1",
+    "sass": "1.24.4",
     "stylelint": "12.0.1",
     "stylelint-order": "4.0.0",
     "stylelint-scss": "3.13.0"