[WIP] Start tests

[ajyl]

Started creating unittests.

NOTE: I made some changes to module import paths to use absolute paths (ex: from potato.create_task_cli import create_task_cli). This means your PYTHONPATH will need to include the path to this repo.
The easiest way to do so would be something like

$ PYTHONPATH=~/potato python potato/flask_server.py ...

or to add something like

export PYTHONPATH=$PYTHONPATH:/home/.../potato

in your bashrc file.

I am open to discuss if this is the best design choice to make! I mainly made this change such that in tests/test_server.py I can import things from potato.

In order to run the tests, run

pytest

or

(from the root of the repo directory)
PYTHONPATH=. pytest

[davidjurgens]

I think long term, we want potato to be runable via command line like python -m potato so I think this change is reasonable, though it breaks most existing installs, which is unfortunate

[ajyl]

Closing, functionality of this PR can be found in #22