def add
      keyfile = shift_argument
      validate_arguments!

      if keyfile
        Heroku::Auth.associate_key(keyfile)
      else
        # make sure we have credentials
        Heroku::Auth.get_credentials
        Heroku::Auth.associate_or_generate_ssh_key
      end
    end
def add
      keyfile = shift_argument
      validate_arguments!

      if keyfile
        Heroku::Auth.associate_key(keyfile)
      else
        # make sure we have credentials
        Heroku::Auth.get_credentials
        Heroku::Auth.associate_or_generate_ssh_key
      end
    end
keys:add [KEY]

 add a key for the current user

 if no KEY is specified, will try to find ~/.ssh/id_[rd]sa.pub

Examples:

 $ heroku keys:add
 Could not find an existing public key.
 Would you like to generate one? [Yn] y
 Generating new SSH public key.
 Uploading SSH public key /.ssh/id_rsa.pub... done

 $ heroku keys:add /my/key.pub
 Uploading SSH public key /my/key.pub... done