Added a way to modify the oauth_callback url

[scottsampson]

If you add the following to your config options the callback url will take you back to the /users page of your project and then work with devise.

twitter.consumer_secret =
twitter.consumer_key =
twitter.options({
:site => 'http://twitter.com',
:oauth_callback => (BASE_URL.end_with?('/') ? BASE_URL[0..-2] : BASE_URL) + '/users',
:oauth_callback_confirmed => 'true'
})

Then set BASE_URL in your environments files. For my dev environment it would be something along the lines of:

BASE_URL = "http://localhost"