Added support for multiple API versions (#533)

* Added support for multiple API versions

Note that no changes were made to the api, the code was refactored to allow for new versions of the api to be created down the road.

Here's what this would look like:
+-- api/
    +-- v1/
        +-- __init__.py
        +-- resources.py
    +-- v1_1/
        +-- __init__.py
        +-- resources.py
    +-- v2/
        +-- __init__.py
        +-- resources.py
    +-- __init__.py
    +-- common.py

* reformatted using black

/Users/drthrash/PycharmProjects/ihatemoney/ihatemoney/api/v1/resources.py
reformatted /Users/drthrash/PycharmProjects/ihatemoney/ihatemoney/api/common.py
All done! ✨ 🍰 ✨

* Applying fix for unused import in init.py

https://stackoverflow.com/questions/31079047/python-pep8-class-in-init-imported-but-not-used

* Formatting changes recommended by black

All done! ✨ 🍰 ✨
1 file reformatted, 22 files left unchanged.

0 files changed, 0 insertions, 0 deletions