Remove Twitter job and add it to third party list.

Making use of Twitter gem because API v1 deprecation will break the Twitter job.
So kevinthompson proposed to remove it form the template.

The Twitter REST API v1 will officially retire on Tuesday, May 7, 2013.

"Requests to search.twitter.com/search.* will receive HTTP 410 Gone. Use GET search/tweets instead."

Source: https://dev.twitter.com/blog/api-v1-retirement-final-dates
Twitter gem: https://github.com/sferik/twitter