- extend `pytest` with an option to run only the minimum number
of (unit) test cases to just keep the coverage at 100%
- rationale:
+ many of the unit test cases partly overlap with
respect to the lines of source code executed
+ also, integration tests, by definition, do not
contribute to a higher test coverage
- implementation: mark "redundant" test cases as one of:
+ `pytest.mark.integration_test`
=> code usage from the perspective of the end user
+ `pytest.mark.overlapping_test`
=> tests not contributing to the 100% coverage
+ `pytest.mark.sanity_test`
=> tests providing confidence in the test data
- add `tests.conftest` module
=> programatically convert the above markers into
`@pytest.mark.no_cover` and collect the non-"redundant" tests
- add nox session "test-fast" to run only the minimum
number of (unit) test while holding coverage at 100%
- refactor some test modules
+ wrap some test cases in a class
+ move sanity tests to the end of the files
- make `GF2`, `one`, and `zero`, defined in the `lalib.elements.gf2`
module, available as top-level imports for the `lalib` package
via `from lalib import *`
- provide some code snippets in the package's docstring
- test the star import
