Rename edx-tim to ora2

Coordinating this transition is going to be a little tricky, but it makes sense to do it ahead of the deploy to stage.  I'm planning to:

1) Merge this branch.
2) Rename the GitHub repo.
3) Update the edx-platform installation branch to point to the new repo.
4) Update Travis and Coveralls to point to the new repo.
5) Update readthedocs to point to the new repo.

In addition, this require that we uninstall `edx-tim` from any environment in which it's currently installed, including:
* The performance test environment
* Devstack VMs
* Sandboxes

@ormsbee