Bedtools subworkflow (containing bedtools genomecov and bedtools merge modules)

[rnaidu]

PR checklist

• [ ] adding bedtools genomecov module.
• [ ] adding bedtools merge module.
• [ ] If you've fixed a bug or added code that should be tested, add tests!
• [ ] If you've added a new tool - have you followed the module conventions in the contribution docs
• [ ] If necessary, include test data in your PR.
• [ ] Remove all TODO statements.
• [ ] Emit the versions.yml file.
• [ ] Follow the naming conventions.
• [ ] Follow the parameters requirements.
• [ ] Follow the input/output options guidelines.
• [x] Add a resource label
• [ ] Use BioConda and BioContainers if possible to fulfil software requirements.
• Ensure that the test works with either Docker / Singularity. Conda CI tests can be quite flaky:
  • [ ] nf-test test --profile=docker --tag
  • [ ] nf-test test --profile=singularity --tag
  • [ ] nf-test test --profile=conda --tag

[rhshah]

I am not sure if we need to do this, nf-core should have them https://github.com/nf-core/modules/tree/master/modules/nf-core/bedtools