Migrate test calls from nosetests to pytest.

.coveragerc

.gitlab-ci.yml

Makefile

setup.py

tests/gitlab_CI_docker/context/environment_spechomo.yml

tests/test_classifier.py

tests/test_classifier_creation.py

tests/test_clustering.py

tests/test_prediction.py

tests/test_resampling.py

tests/test_utils.py