Router refactoring

This is an attempt to clean up our router to follow current Ember.js best practices. While rewriting travis-web to work on the ~1.0 version of Ember.js I was trying to make it work without changing too much things, but this code is an obstacle in adding new features and working with the codebase.

Besides things currently pushed here, I will also try to refactor 2 other things which aren't optimal:

* a way we handle tabs. we use custom `activate` function on a `repo` and `profile` controllers to manage tabs, I think that it may be changed to require less overriding of `setupController` just to activate a tab
* change a way we do layouts. I'm not sure yet what would be the best solution, but we need to do a lot of custom logic in our routes to handle layouts at the moment. This is not really troubling as the code there is rather straightforward and I will not sweat over it, but it will be nice to find out if there are any better approaches.