Bump node-sass@^4.8.3

Make the latest stable node-sass the minimum.

Author: xzyfer

package.json

@@ -23,7 +23,7 @@
   "dependencies": {
     "gulp-util": "^3.0",
     "lodash.clonedeep": "^4.3.2",
-    "node-sass": "^4.8.1",
+    "node-sass": "^4.8.3",
     "through2": "^2.0.0",
     "vinyl-sourcemaps-apply": "^0.2.0"
   },