Rails on Tutorial の１．５．２の箇所です。
Herokuにデプロイ後、アプリを起動するとApplicationErrorと出ます。
ログは以下のとおりです。

2018-07-02T22:53:39.010497+00:00 app[api]: Release v1 created by user 
2018-07-02T22:53:39.010497+00:00 app[api]: Initial release by user 
2018-07-02T22:53:39.140128+00:00 app[api]: Enable Logplex by user 
2018-07-02T22:53:39.140128+00:00 app[api]: Release v2 created by user 
2018-07-02T22:54:02.000000+00:00 app[api]: Build started by user 
2018-07-02T22:54:51.413879+00:00 app[api]: Set LANG, RACK_ENV, RAILS_ENV, RAILS_LOG_TO_STDOUT, RAILS_SERVE_STATIC_FILES, SECRET_KEY_BASE config vars by user
2018-07-02T22:54:51.413879+00:00 app[api]: Release v3 created by user 
2018-07-02T22:54:53.278102+00:00 app[api]: Attach DATABASE (@ref:postgresql-reticulated-10466) by user 
2018-07-02T22:54:53.278102+00:00 app[api]: Release v4 created by user 
2018-07-02T22:54:53.612072+00:00 app[api]: Release v5 created by user 
2018-07-02T22:54:53.626080+00:00 app[api]: Scaled to console@0:Free rake@0:Free web@1:Free worker@0:Free by user
2018-07-02T22:54:53.612072+00:00 app[api]: Deploy 57e7ab4f by user 
2018-07-02T22:54:56.589176+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 55797 -e production`
2018-07-02T22:54:56.466976+00:00 heroku[web.1]: Restarting
2018-07-02T22:54:56.688603+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 7100 -e production`
2018-07-02T22:54:56.000000+00:00 app[api]: Build succeeded
2018-07-02T22:54:58.237948+00:00 app[web.1]: bash: bin/rails: No such file or directory
2018-07-02T22:54:58.295492+00:00 heroku[web.1]: Process exited with status 127
2018-07-02T22:54:58.311557+00:00 heroku[web.1]: State changed from starting to crashed
2018-07-02T22:54:58.313618+00:00 heroku[web.1]: State changed from crashed to starting
2018-07-02T22:54:58.570294+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 27637 -e production`
2018-07-02T22:55:00.743445+00:00 heroku[web.1]: Process exited with status 127
2018-07-02T22:55:00.675547+00:00 app[web.1]: bash: bin/rails: No such file or directory
2018-07-02T22:55:00.760182+00:00 heroku[web.1]: State changed from starting to crashed
2018-07-02T22:55:00.915137+00:00 app[web.1]: Puma starting in single mode...
2018-07-02T22:55:00.915146+00:00 app[web.1]: * Environment: production
2018-07-02T22:55:00.915206+00:00 app[web.1]: * Listening on tcp://0.0.0.0:55797
2018-07-02T22:55:00.915542+00:00 app[web.1]: Use Ctrl-C to stop
2018-07-02T22:55:00.915117+00:00 app[web.1]: => Booting Puma
2018-07-02T22:55:00.915136+00:00 app[web.1]: => Run `rails server -h` for more startup options
2018-07-02T22:55:00.915135+00:00 app[web.1]: => Rails 5.1.4 application starting in production
2018-07-02T22:55:00.915145+00:00 app[web.1]: * Min threads: 5, max threads: 5
2018-07-02T22:55:00.915144+00:00 app[web.1]: * Version 3.9.1 (ruby 2.4.4-p296), codename: Private Caller
2018-07-02T22:55:02.424199+00:00 app[web.1]: === puma shutdown: 2018-07-02 22:55:02 +0000 ===
2018-07-02T22:55:02.423964+00:00 app[web.1]: - Gracefully stopping, waiting for requests to finish
2018-07-02T22:55:02.424251+00:00 app[web.1]: - Goodbye!
2018-07-02T22:55:02.424361+00:00 app[web.1]: Exiting
2018-07-02T22:55:02.370949+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2018-07-02T22:55:02.526077+00:00 heroku[web.1]: Process exited with status 0
2018-07-02T22:57:01.286647+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=peaceful-wildwood-16858.herokuapp.com request_id=fc3cd9b8-0934-4890-815f-3c70f95125d5 fwd="126.236.6.5" dyno= connect= service= status=503 bytes= protocol=https
2018-07-02T22:57:09.898089+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=peaceful-wildwood-16858.herokuapp.com request_id=6a98fd7f-f906-48e7-a0c8-bb6660494d0f fwd="126.236.6.5" dyno= connect= service= status=503 bytes= protocol=https
2018-07-02T22:57:15.792947+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=peaceful-wildwood-16858.herokuapp.com request_id=ee84e173-b341-42c7-8c83-65495200f37d fwd="126.236.6.5" dyno= connect= service= status=503 bytes= protocol=https
2018-07-02T23:02:27.360839+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=peaceful-wildwood-16858.herokuapp.com request_id=cf72be62-b79a-4eb1-8a4d-3a1eebc21005 fwd="126.236.6.5" dyno= connect= service= status=503 bytes= protocol=https
2018-07-02T23:03:04.792630+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=peaceful-wildwood-16858.herokuapp.com request_id=72cca4b2-6eb2-414a-93ef-3e0372be5f4d fwd="126.236.6.5" dyno= connect= service= status=503 bytes= protocol=http

いくつかのサイトを参考にしたところ、.gitignoreファイルが影響しているとのことで確認しましたが、 binフォルダは指定されていませんでした。

.gitignoreの内容：

    # See https://help.github.com/articles/ignoring-files for more about ignoring files.
    #
    # If you find yourself ignoring temporary files generated by your text editor
    # or operating system, you probably want to add a global ignore instead:
    #   git config --global core.excludesfile '~/.gitignore_global'

    # Ignore bundler config.
    /.bundle

    # Ignore bundler gems.
    vendor/bundle

    # Ignore the default SQLite database.
    /db/*.sqlite3
    /db/*.sqlite3-journal

    # Ignore all logfiles and tempfiles.
    /log/*.log
    /tmp

    # Ignore other unneeded files.
    doc/
    *.swp
    *~
    .project
    .DS_Store
    .idea
    .secret

heroku上にも bin/railsはあるようです。

   ~ $ ls
    app  bin  config  config.ru  db  Gemfile  Gemfile.lock  lib  log  package.json  public  Rakefile  README.md  test  tmp  vendor
    ~ $ ls bin
    bundle  erb  gem  irb  node  rails  rake  rdoc  ri  ruby  ruby.exe  setup  spring  update  yarn

エラーは別の部分で起きているのでしょうか？
どなたかアドバイスいただけると大変ありがたいですm(__)m