Consider separating cookbooks into separate repos

Hey guys,

How would you feel about separating cookbooks into different repositories? This is actually the official convention for Chef now. We could start a new org called "travis-cookbooks" to help keep it organized. We could also pull the cookbooks back into the main repo (the container repo that replaces this one) using librarian (or alternatively berkshelf, if anyone feels strongly that its the better option).

### Benefits
- easier means of sharing cookbook with community, and swapping custom-baked travis cookbooks for community-supported cookbooks
- easier for user to re-use cookbooks. librarian makes it possible [to pull individual cookbooks out of the current repo](https://github.com/myplanetdigital/jenkins-inception/blob/develop/Cheffile#L41-L45), but it involves cloning the whole 100MB repo just to get --say-- the xserver cookbook.
- more likely that those outside the travis project will contribute to cookbooks