title: Rails error when I try generate a scaffold
body: <p>Sorry for my english I'm french ;)</p>
  
  <p>When I try to generate a scaffold with <code>rails g scaffold (data info)</code> I have an error and i have never see this</p>
  
  <pre><code>rails g scaffold title:string language:string engine:string little_description:string description:text on_production:boolean game_type:string platform:string dimension:string
        invoke  active_record
  Traceback (most recent call last):
      34: from bin/rails:4:in '&lt;main&gt;'
      33: from bin/rails:4:in 'require'
      32: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/commands.rb:16:in '&lt;top (required)&gt;'
      31: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/command.rb:44:in 'invoke'
      30: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/command/base.rb:63:in 'perform'
      29: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor.rb:387:in 'dispatch'
      28: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in 'invoke_command'
      27: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/command.rb:27:in 'run'
      26: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/commands/generate/generate_command.rb:24:in 'perform'
      25: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/generators.rb:269:in 'invoke'
      24: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/base.rb:466:in 'start'
      23: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/group.rb:232:in 'dispatch'
      22: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'invoke_all'
      21: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'map'
      20: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'each'
      19: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'block in invoke_all'
      18: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in 'invoke_command'
      17: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/command.rb:27:in 'run'
      16: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/group.rb:133:in '_invoke_from_option_orm'
      15: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/group.rb:266:in '_invoke_for_class_method'
      14: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/shell.rb:68:in 'with_padding'
      13: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/group.rb:277:in 'block in _invoke_for_class_method'
      12: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:115:in 'invoke'
      11: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/group.rb:232:in 'dispatch'
      10: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'invoke_all'
       9: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'map'
       8: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'each'
       7: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in 'block in invoke_all'
       6: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in 'invoke_command'
       5: from /usr/local/lib/ruby/gems/2.5.0/gems/thor-0.20.0/lib/thor/command.rb:27:in 'run'
       4: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/generators/named_base.rb:236:in 'block in check_class_collision'
       3: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/generators/base.rb:249:in 'class_collisions'
       2: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/generators/base.rb:249:in 'each'
       1: from /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/generators/base.rb:258:in 'block in class_collisions'
  /usr/local/lib/ruby/gems/2.5.0/gems/railties-5.1.4/lib/rails/generators/base.rb:258:in 'const_defined?': wrong constant name Title:string (NameError)
  </code></pre>
  
  <p>You know what is the solution 
  I think the problem come of active record.</p>
  
  <p>Thanks</p>