Wrap main() so it can be tested in an easier way

The idea is to test exporting code using Dart test runner,
it will make it easier to write cross platform integration
tests for the various command line options.

Author: tmpsantos

bin/flutterflow_cli.dart

@@ -5,7 +5,7 @@ import 'package:flutterflow_cli/src/flutterflow_api_client.dart';
 
 const kDefaultEndpoint = 'https://api.flutterflow.io/v1';
 
-void main(List<String> args) async {
+Future<void> appMain(List<String> args) async {
   final parsedArguments = _parseArgs(args);
 
   final token =
@@ -181,3 +181,7 @@ ArgResults _parseArgs(List<String> args) {
 
   return parsed;
 }
+
+void main(List<String> args) async {
+  await appMain(args);
+}