run method
Runs this command.
The return value is wrapped in a Future if necessary and returned by
CommandRunner.runCommand.
Implementation
@override
Future<int> run() async {
await runPub(this, sharedLibraryDirectory, ["upgrade"]);
await runPub(this, serverDirectory, ["upgrade"]);
await runPub(this, generatedClientDirectory, ["upgrade"]);
await runPub(this, applicationDirectory, ["upgrade"]);
return ExitCode.success.code;
}