Doesn't play well with the jnunemaker/twitter gem

[htapal]

I'm using devise-twitter only for connecting my devise user to Twitter. Since devise-twitter does not have hooks to perform status updates, I attempted to use the twitter gem by jnunemaker. However, since the jnunemaker's class is named Twitter that collides with the warden strategy class name as it attempts to use :twitter (passed from the Devise::Twitter.set) to check if a class is available and that causes errors regarding authenticate! method not being available.

It may make sense to use :devise_twitter as the strategy name so that it doesn't collide with the twitter gem class.