cloud9でrailsに作成したテーブルにカルムを追加したい

cloud9でrailsに作ったテーブルにカラム情報を追加したい

rails generate modelで作成したtable

class CreateUsers < ActiveRecord::Migration[5.0]
  def change
    create_table :users do |t|
      t.string :name
      t.string :email

      t.timestamps
    end
  end
end

これに、カラム名：image_name 型：stringを追加する

rails g migration add_image_name_to_usersを実行すると・・・

NoMethodError: undefined method `add_image_name_to_Users' for main:Object
        from (irb):46
        from /usr/local/rvm/gems/ruby-2.4.0/gems/railties-5.0.5/lib/rails/commands/console.rb:65:in `start'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/railties-5.0.5/lib/rails/commands/console_helper.rb:9:in `start'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/railties-5.0.5/lib/rails/commands/commands_tasks.rb:78:in `console'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/railties-5.0.5/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/railties-5.0.5/lib/rails/commands.rb:18:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:293:in `require'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:293:in `block in require'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:259:in `load_dependency'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:293:in `require'
        from /home/ubuntu/workspace/app1/bin/rails:9:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:287:in `load'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:287:in `block in load'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:259:in `load_dependency'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/activesupport-5.0.5/lib/active_support/dependencies.rb:287:in `load'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/commands/rails.rb:6:in `call'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/command_wrapper.rb:38:in `call'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application.rb:201:in `block in serve'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application.rb:171:in `fork'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application.rb:171:in `serve'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application.rb:141:in `block in run'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application.rb:135:in `loop'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application.rb:135:in `run'
        from /usr/local/rvm/gems/ruby-2.4.0/gems/spring-2.0.2/lib/spring/application/boot.rb:19:in `<top (required)>'
        from /usr/local/rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require'
        from /usr/local/rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/rubygems/core_ext/kernel_require.rb:55:in `require'
        from -e:1:in `<main>'

となる。調べたら、rails g migration add_カラム名_to_テーブル名で
実行可能となっていました。"cloud9"ではエラーになりましたが、コマンドが間違っているのでしょうか？