title: heroku push code error ruby on rails mac os
body: <p>This is my output at mac terminal and heroku master branch:</p>
  
  <pre><code>[remote rejected] master -&gt; master (pre-receive hook declined)
      error: failed to push some refs to 'https://git.heroku.com/projectname.git'
      In heroku
      -----&gt; Ruby app detected
      -----&gt; Compiling Ruby/Rails
      -----&gt; Using Ruby version: ruby-2.0.0
      -----&gt; Installing dependencies using 1.9.7
             Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4 --deployment
             You are trying to install in deployment mode after changing
             your Gemfile. Run `bundle install` elsewhere and add the
             updated Gemfile.lock to version control.
             You have added to the Gemfile:
             * ruby (= 2.0.0)
             * pg (= 0.17.1)
             Bundler Output: You are trying to install in deployment mode after changing
             your Gemfile. Run `bundle install` elsewhere and add the
             updated Gemfile.lock to version control.
  
             You have added to the Gemfile:
             * ruby (= 2.0.0)
             * pg (= 0.17.1)
       !
       !     Failed to install gems via Bundler.
       !
       !     Push rejected, failed to compile Ruby app
  </code></pre>