Moved Followers and Followings into one module, with an abstract class
Basic followings blueprint, currently untested
Default to subdomains mode when running tests

* Fixed a bug where using `--mode domains` would break py.test
Removed debug statments
Following tests and modifications to the following blueprint

I've experimented with a new style of defining endpoints in the
followings blueprint, resulting in much clearer endpoint names.

For example, 'followings.followings' is now 'followings.all', and
specific methods have their own endpoints (e.g. 'following.delete')
Merge branch 'feature/77-relationships' into develop

* feature/77-relationships:
  Following tests and modifications to the following blueprint
  Removed debug statments
  Default to subdomains mode when running tests
  Basic followings blueprint, currently untested
  Moved Followers and Followings into one module, with an abstract class