title: Scope doesn't receive array as argument
body: <p>I have the following scope defined in my model:</p>
  
  <pre><code>  scope :answers_in, -&gt; (answers = nil) do
      return unless answers.present?
      where(answer_1: answers).or(where(answer_2: answers))
    end
  </code></pre>
  
  <p>The <code>answers</code> should by an array. However, when I make a call passing an array, receive an argument error:</p>
  
  <pre><code>AnswerConnection.answers_in([1, 2])
  ArgumentError: wrong number of arguments (given 2, expected 0..1)
          from /vagrant/farma_alg_reborn/app/models/answer_connection.rb:7:in `block in &lt;class:AnswerConnection&gt;'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/scoping/named.rb:159:in `instance_exec'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/scoping/named.rb:159:in `block (2 levels) in scope'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/relation.rb:351:in `scoping'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/scoping/named.rb:159:in `block in scope'
          from (irb):2
          from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/console.rb:65:in `start'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/console_helper.rb:9:in `start'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:78:in `console'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/railties-5.0.1/lib/rails/commands.rb:18:in `&lt;top (required)&gt;'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:293:in `require'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:293:in `block in require'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:293:in `require'
          from /vagrant/farma_alg_reborn/bin/rails:9:in `&lt;top (required)&gt;'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:287:in `load'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:287:in `block in load'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:259:in `load_dependency'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/activesupport-5.0.1/lib/active_support/dependencies.rb:287:in `load'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/commands/rails.rb:6:in `call'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/command_wrapper.rb:38:in `call'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:191:in `block in serve'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:161:in `fork'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:161:in `serve'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:131:in `block in run'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:125:in `loop'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application.rb:125:in `run'
          from /usr/local/rvm/gems/ruby-2.3.1/gems/spring-2.0.0/lib/spring/application/boot.rb:19:in `&lt;top (required)&gt;'
          from /usr/local/rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
          from /usr/local/rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
          from -e:1:in `&lt;main&gt;'
  </code></pre>
  
  <p>Is this a bug, Rails scopes doesn't work with arrays or I'm doing something wrong?</p>