Tests rely on pytest, so make sure you install that.

Run all tests (from the Tests directory) (~630 s):
pytest

Run all fast tests (~60 s):
pytest -k "not slow"

Run all but very slow tests (~120 s)
pytest -m "not very_slow"


When making tests, use:
@pytest.mark.new

To mark new tests. And then use:
pytest -m "new"

To run just the new tests, instead of having to rerun the entire set of tests
every time you add/modify one.

use -s to allow things to print to screen
