Major changes:
- kraken for contamination screens, with some updated organism features (viruses, bacterial contamination, ...)
- readthedocs
- flow cells without an index are possible
Minor changes:
- including docs link / build badges, and readme updates
- stripped env name in conda environment
- purge fastqscreen dependencies
- diskspace in periphery is included in the email
- precommit for flake8 test
- pytests include mask calculation for common use cases
- cleaned up 'float reporting' in mqc report & email.