Linting
- Fixes linting
- Creates a linting job on CI
- Fixes depricated warnings for the tests
- Makes compatible with Python 3.10 (3.11 is not possible for the moment as numba and wikiextractor do not support)
- Replaces nose for testing with pytest (nose version is not compatible with Python 3.10)
- Fixes problems for transition to pytest
- Modifies GitLab jobs to run tests for Python 3.8, 3.9 and 3.10, creates coverage report only for 3.10