title: Access user in Warden before_failure callback
body: <p>Is there a way to access the user that failed authentication via the <code>before_failure</code> <a href="https://github.com/wardencommunity/warden/wiki/Callbacks" rel="nofollow noreferrer">callback</a>?</p>
  <pre><code>Warden::Manager.before_failure do |env, opts|
    request = Rack::Request.new(env)
    env['SCRIPT_INFO'] =~ /\/(.*)/
    request.params[:action] = $1
  end
  </code></pre>
  <p>I am placing this configuration in the devise initializer, I have heard other people mention placing it in the user model so maybe I can access it that way.</p>