title: ERROR: While executing gem ... (Gem::CommandLineError)
body: <p>I am getting the below error while releasing and pushing the gem. I tried installing it multiple times. Ruby Version is 2.2.9</p>
  <pre><code>ERROR:  While executing gem ... (Gem::CommandLineError)
   Unknown command bump
  
   ERROR:  While executing gem ... (Gem::CommandLineError)
    Unknown command release
  </code></pre>
  <p>I am running from the script and the script has the following lines:-</p>
  <pre><code>bundle install --deployment
  gem install release -v '~&gt; 0.4.0'
  bundle exec gem release --tag --host http://rubygems/
  gem install bump -v 0.8.0
  bundle exec gem bump --push
  </code></pre>
  <p>Following is the log</p>
  <pre><code>Installing ri documentation for release-0.4.0
  Done installing documentation for highline, visionmedia-commander, release after 3 seconds
  3 gems installed
  **ERROR:  While executing gem ... (Gem::CommandLineError)
   Unknown command release**
  Successfully installed bump-0.8.0
  Parsing documentation for bump-0.8.0
  Installing ri documentation for bump-0.8.0
  Done installing documentation for bump after 0 seconds
  1 gem installed
   **ERROR:  While executing gem ... (Gem::CommandLineError)
    Unknown command bum**p
    
  </code></pre>
  <p>Added the dependency in Gemfile. Below is the Gemfile</p>
  <pre><code>  source 'http://rubygems'
    gem 'bump', '~&gt; 0.8.0'
    gem 'release', '~&gt; 0.4.0'
  </code></pre>