Change push to accept an optional argument as show in the official documentation of push for JS
Change push to accept an optional argument as show in the official documentation of push for JS

kevmoo/firebase-dart,sirctseb/firebase-dart,ronlobo/firebase-dart,ronlobo/firebase-dart,sirctseb/firebase-dart,kasperpeulen/firebase-dart,collinjackson/firebase2-dart,kasperpeulen/firebase-dart,collinjackson/firebase2-dart,kevmoo/firebase-dart,collinjackson/firebase2-dart,ronlobo/firebase-dart,kevmoo/firebase-dart,sirctseb/firebase-dart,collinjackson/firebase2-dart,kasperpeulen/firebase-dart