Mutacc

Fixed
- Picard version in Dockerfile to be 3.1.0

Fixed
- workflow step version in `docker_build_n_publish` GitHub action

Added
- Integration test with MongoDB v7
Changed
- Moved tests and coverage from Travis to GitHub actions
- Updated python version and versions of some GitHub actions
- Unfreeze cyvcf2 lib to be able to install the software with Python>=3.8
- Installation instructions on README page to install mutacc using Python 3.8
- Unfreeze pymongo requirement and removed deprecated pymongo code to support latest version of MongoDB
- Updated pythin version to 3.11 in Dockerfile
- Updated MongoDB version to 7 in docker-compose.yml file
Fixed
- Badge on Readme page
- GitHub action to push the right image to Docker Hub
- Replaced deprecated `pkg_resources` lib with `importlib_resources`
- Path to app in tests_and_coverage.yml, coveralls step

Fixed
- Freeze PyMongo lib to version<4.0 to keep supporting previous MongoDB versions

Fixed
- Token name used by PyPI push action once again

Fixed
- Token name used by PyPI push action