RO-Crate reporting

[douglowe]

This is an issue for creating an RO-Crate report option, as an alternative to the html report option.

[douglowe]

Actions:

• duplicate tests/test_report directory, to tests/test_report_rocrate, and create example ro-crate in that directory
• add function test_report_rocrate to tests/tests.py
• add ro-crate libraries to testing environment
• follow trail from create_report in snakemake/api.py to find where we can branch to new report functionality
• inside snakemake/report create rocrate_reporter directory
• plan out rocrate reporting functions

[stain]

@douglowe investigating the different profiles for workflow (plan+execution)s in RO-Crate. Considering making a template crate that can then be added onto with workflow outputs.