speed up file uploads

lib/helpers/firebase_helper.dart

@@ -23,6 +23,17 @@ Future<Map> getClaims({bool refreshIdToken = false}) async {
   return idToken.claims;
 }
 
+// returns list of url
+Future<List<String>> uploadFiles(String path, List<File> files,
+    {String fileName}) async {
+  List<Future<String>> fu = [];
+  for (File f in files) {
+    Future<String> u = uploadStorage(path, f);
+    fu.add(u);
+  }
+  return Future.wait(fu);
+}
+
 Future<String> uploadStorage(String path, File file, {String fileName}) async {
   if (fileName == null) {
     fileName = Uuid().v4();