title: NoMethodError: undefined method `[]' for #<ActiveRecord::Migration:0x000000033fedc0>
body: <p>I am new to Ruby on rails, I am doing a facebook and google authentication using omni_auth and stuck in this!</p>
  
  <p>When I run rake db:migrate, show the following error:</p>
  
  <pre><code>rake aborted!
  NoMethodError: undefined method `[]' for #&lt;ActiveRecord::Migration:0x000000033fedc0&gt;
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:664:in `block in method_missing'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in `block in say_with_time'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in `say_with_time'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:654:in `method_missing'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:416:in `method_missing'
  /home/ubuntu/rails_project/Devise-Omniauth/db/migrate/20180129115427_update_users.rb:1:in `&lt;top (required)&gt;'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:777:in `load_migration'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:773:in `migration'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:768:in `disable_ddl_transaction'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1051:in `use_transaction?'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:961:in `rescue in block in migrate'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:958:in `block in migrate'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in `each'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in `migrate'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:823:in `up'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:801:in `migrate'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
  /usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-4.2.5/lib/active_record/railties/databases.rake:44:in `block (2 levels) in &lt;top (required)&gt;'
  /usr/local/rvm/gems/ruby-2.3.0/gems/rake-12.3.0/exe/rake:27:in `&lt;top (required)&gt;'
  /usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval'
  /usr/local/rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `&lt;main&gt;'
  </code></pre>
  
  <p>This is causing due to this file:</p>
  
  <pre><code>class UpdateUsers &lt; ActiveRecord::Migration[5.0]
    def change
      add_column(:users, :provider, :string, limit: 50, null: false, default: '')
      add_column(:users, :uid, :string, limit: 500, null: false, default: '')
    end
  end
  </code></pre>