docs: def install_ruby(ruby, runas=None, opts=None, env=None):
      '''
      Install a ruby implementation.
  
      ruby
          The version of ruby to install
  
      runas
          The user under which to run rvm. If not specified, then rvm will be run
          as the user under which Salt is running.
  
      env
          Environment to set for the install command. Useful for exporting compilation
          flags such as RUBY_CONFIGURE_OPTS
  
      opts
          List of options to pass to the RVM installer (ie -C, --patch, etc)
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' rvm.install_ruby 1.9.3-p385
      '''
      # MRI/RBX/REE dependencies for Ubuntu 10.04:
      #   build-essential openssl libreadline6 libreadline6-dev curl
      #   git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0
      #   libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev autoconf libc6-dev
      #   libncurses5-dev automake libtool bison subversion ruby
      if opts is None:
          opts = []
  
      if runas and runas != 'root':
          _rvm(['autolibs', 'disable', ruby] + opts, runas=runas)
          opts.append('--disable-binary')
      return _rvm(['install', ruby] + opts, runas=runas, env=env)