Merge pull request #3454 from hosseinsh/gulp-buffer

Addressing Gulp Deprecation warning

gulp/build.js

@@ -40,7 +40,7 @@ function replaceAll(string, find, replace) {
 function stringSrc(filename, string) {
   let src = require('stream').Readable({objectMode: true});
   src._read = function () {
-    this.push(new gutil.File({cwd: '', base: '', path: filename, contents: new Buffer(string)}));
+    this.push(new gutil.File({cwd: '', base: '', path: filename, contents: Buffer.from(string)}));
     this.push(null);
   };
   return src;