title: A rake task from a gem doesn't show up in a Rails application
body: <p>I'm building a gem with a list of rake tasks. I have this:</p>
  
  <pre><code>#/lib/tasks/my_gem.rake:
  
  namespace :my_gem do
    task :task1 do
      puts "Hello"
    end
  end
  </code></pre>
  
  <p>I install the gem to a rails application and run <strong>rake -T</strong>. And there's no task "task1" or anything related to "my_gem".</p>