Trailing slash

* made haruploader tolerate url's with a trailing slash
* unit tests for above
* editied test_config.yaml and changed url's to a single URL pointed at example.com, so the acceptance test runs faster and doesn't access edx.org.

/cc @clytwynec @benpatterson @jzoldak  
I'd rather see this tested in the context of the uploader, instead of testing that urlparse itself works.  Right now, if we reverted the change in haruploader.py, these tests would still pass.