title: missing required flag heroku tail
body: <p>I am working to deploy my rails app. Everything in running in local environment  but I am having some issues making my first push to heroku. I am getting the standard app error, see pic: </p>
  
  <p><a href="https://i.stack.imgur.com/HJfhd.png" rel="noreferrer"><img src="https://i.stack.imgur.com/HJfhd.png" alt="enter image description here"></a></p>
  
  <p>when i run the command heroku logs --tail, i get the following error:</p>
  
  <p><a href="https://i.stack.imgur.com/TjOxd.png" rel="noreferrer"><img src="https://i.stack.imgur.com/TjOxd.png" alt="enter image description here"></a></p>
  
  <p>my gemfile is as so: </p>
  
  <pre><code>source 'https://rubygems.org'
  
  
  # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
  gem 'rails', '4.2.6'
  # Use sqlite3 as the database for Active Record
  
  # Use SCSS for stylesheets
  gem 'sass-rails', '~&gt; 5.0'
  # Use Uglifier as compressor for JavaScript assets
  gem 'uglifier', '&gt;= 1.3.0'
  # Use CoffeeScript for .coffee assets and views
  gem 'coffee-rails', '~&gt; 4.1.0'
  # See https://github.com/rails/execjs#readme for more supported runtimes
  # gem 'therubyracer', platforms: :ruby
  
  # Use jquery as the JavaScript library
  gem 'jquery-rails'
  # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
  gem 'turbolinks'
  # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
  gem 'jbuilder', '~&gt; 2.0'
  # bundle exec rake doc:rails generates the API under doc/api.
  gem 'sdoc', '~&gt; 0.4.0', group: :doc
  
  # Use ActiveModel has_secure_password
  # gem 'bcrypt', '~&gt; 3.1.7'
  
  # Use Unicorn as the app server
  # gem 'unicorn'
  
  # Use Capistrano for deployment
  # gem 'capistrano-rails', group: :development
  
  group :development, :test do
    # Call 'byebug' anywhere in the code to stop execution and get a debugger console
    gem 'byebug'
  end
  
  group :development do
    gem 'sqlite3'
  
    # Access an IRB console on exception pages or by using &lt;%= console %&gt; in views
    gem 'web-console', '~&gt; 2.0'
  
    group :production do
       gem 'pg'
  end
  
    # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
    gem 'spring'
  end
  </code></pre>
  
  <p>below are my heroku logs: </p>
  
  <p>2</p>
  
  <pre><code>018-02-09T00:48:11.108425+00:00 app[web.1]:     from /app/vendor/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:68:in `require'
  
  2018-02-09T00:48:11.108427+00:00 app[web.1]:    from /app/vendor/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:68:in `require'
  
  2018-02-09T00:48:11.108435+00:00 app[web.1]:    from bin/rails:3:in `load'
  
  2018-02-09T00:48:11.108437+00:00 app[web.1]:    from bin/rails:3:in `&lt;main&gt;'
  
  2018-02-09T00:48:11.120606+00:00 app[web.1]: =&gt; Booting WEBrick
  
  2018-02-09T00:48:11.120615+00:00 app[web.1]: =&gt; Rails 4.2.6 application starting in production on http://0.0.0.0:52651
  
  2018-02-09T00:48:11.120619+00:00 app[web.1]: =&gt; Ctrl-C to shutdown server
  
  2018-02-09T00:48:11.120618+00:00 app[web.1]: =&gt; Run `rails server -h` for more startup options
  
  2018-02-09T00:48:11.120621+00:00 app[web.1]: Exiting
  
  2018-02-09T00:49:30.407211+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=postcable.herokuapp.com request_id=ec520950-df52-44ee-95aa-890d9ad76949 fwd="67.20.250.6" dyno= connect= service= status=503 bytes= protocol=https
  
  2018-02-09T00:49:32.372812+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=postcable.herokuapp.com request_id=ffdb944b-9293-4d96-8986-b0af2974704c fwd="67.20.250.6" dyno= connect= service= status=503 bytes= protocol=https
  </code></pre>