Update gulp-sass

package.json

@@ -63,7 +63,7 @@
     "gulp-cssmin": "~0.1.7",
     "gulp-jshint": "~1.12.0",
     "gulp-rename": "~1.2.2",
-    "gulp-sass": "~3.0.0",
+    "gulp-sass": "~3.1.0",
     "gulp-spawn-mocha": "~2.2.1",
     "gulp-uglify": "~1.4.2",
     "gulp-watch": "~4.3.5",