Update dependency gulp-sass to v4.1.0

Author: renovate-bot

package.json

@@ -23,7 +23,7 @@
     "gulp-imagemin": "6.1.0",
     "gulp-order": "1.2.0",
     "gulp-plumber": "1.2.1",
-    "gulp-sass": "4.0.2",
+    "gulp-sass": "4.1.0",
     "gulp-uglify": "3.0.2"
   }
 }