我正在尝试将我的flask应用程序部署在heroku上。除最后一个步骤外，所有步骤均正常。这是我运行的命令：
git push heroku master
这是我收到的完整消息：
Enumerating objects: 6, done.
Counting objects: 100% (6/6), done.
Delta compression using up to 4 threads
Compressing objects: 100% (3/3), done.
Writing objects: 100% (6/6), 871 bytes | 217.00 KiB/s, done.
Total 6 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Compressing source files... done.
remote: Building source:
remote:
remote: ! No default language could be detected for this app.
remote: HINT: This occurs when Heroku cannot detect the buildpack to use for this application automatically.
remote: See https://devcenter.heroku.com/articles/buildpacks
remote:
remote: ! Push failed
remote: Verifying deploy...
remote:
remote: ! Push rejected to latest-headlines.
remote:
To https://git.heroku.com/latest-headlines.git
! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/latest-headlines.git'
我要去哪里错了？