herokuのデプロイでエラーとなります

Question

Rails
```
herokuへのデプロイで

git push heroku master

をすると下記のエラーに毎回なってしまいます。

どなたかお助けください、、、、

```
remote:  !
remote:  !     Could not detect rake tasks
remote:  !     ensure you can run `$ bundle exec rake -P` against your app
remote:  !     and using the production group of your Gemfile.
remote:  !     rake aborted!
remote:  !     NoMethodError: undefined method `load_tasks' for nil:NilClass
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/Rakefile:6:in `<top (required)>'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/rake_module.rb:29:in `load'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/rake_module.rb:29:in `load_rakefile'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:703:in `raw_load_rakefile'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:104:in `block in load_rakefile'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:186:in `standard_exception_handling'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:103:in `load_rakefile'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:82:in `block in run'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:186:in `standard_exception_handling'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/lib/rake/application.rb:80:in `run'
remote:  !     /tmp/build_5acebea364fb833e47a864863383ebb3/vendor/bundle/ruby/2.4.0/gems/rake-12.3.1/exe/rake:27:in `<top (required)>'
remote:  !     vendor/bundle/bin/rake:17:in `load'
remote:  !     vendor/bundle/bin/rake:17:in `<main>'
remote:  !
remote: /app/tmp/buildpacks/f6d48d8a14fccbb19c0c0402fca224929d18e9ee042b3e204bc5992612e990d3b3a0fb1f9627b1a3bae11e9fa20dffc96e136bd734a2f3cf92a0d05bedd42cfe/lib/language_pack/helpers/rake_runner.rb:106:in `load_rake_tasks!': Could not detect rake tasks (LanguagePack::Helpers::RakeRunner::CannotLoadRakefileError)
remote: ensure you can run `$ bundle exec rake -P` against your app
remote: and using the production group of your Gemfile.
remote: rake aborted!
remote: NoMethodError: undefined method `load_tasks' for nil:NilClass
remote: /tmp/build_5acebea364fb833e47a864863383ebb3/Rakefile:6:in `<top (required)>'

=================


remote:  !     Push rejected, failed to compile Ruby app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...
remote: 
remote: !	Push rejected to ///-27048.
remote: 
To https://git.heroku.com////-27048.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com////-27048.git'
```

Answer 1

Railsは使ったことないですが、他のフレームワークでも躓く点は似ていると思うので、思い当たるものを列挙させてもらいます。
・Gitの「コミット」がちゃんと最後までできてない。
・「Procfile」ファイルを置いてない。