TESTING module pytest

Good practices: 
	https://docs.pytest.org/en/stable/goodpractices.html
Installation and getting started:
	https://docs.pytest.org/en/stable/getting-started.html

Adding it to Conda

https://docs.conda.io/projects/conda-build/en/latest/concepts/recipe.html#testing
https://docs.conda.io/projects/conda-build/en/latest/resources/define-metadata.html#test-section
