chore(): add npm run watch for sass files

gulpfile.js

@@ -13,6 +13,10 @@ gulp.task('sass', function() {
         .pipe(gulp.dest('./static/css'));
 });
 
+gulp.task('watch', function() {
+    gulp.watch('./static/**/*.scss', ['sass']);
+});
+
 gulp.task('default', function() {
     gulp.start('fonts', 'sass');
 });

package.json

@@ -11,6 +11,7 @@
     "gulp-util": "^3.0.7"
   },
   "scripts": {
-    "build": "gulp"
+    "build": "gulp",
+    "watch": "gulp watch"
   }
 }