title: Add gem to gemfile with bundler from command line
body: <p>When using node package manager you can specify <code>npm install --save mynodemodule</code> which automatically pops the module in <code>package.json</code></p>
  
  <p>I was wondering if there is a command for bundler that allows you to add the gem and version to the gemfile from the command line?</p>
  
  <p>For example <code>bundle install --save nokogiri</code></p>