nf-validation on sample sheet

[Daniel-VM]

Sample sheet validation could be performed via nf-validation plugin.
In addition, tsv/csv documentation and parsing will need adjustments.

• Fix README: tsv file extension on sample sheet will fail, change it to csv
  - [ ] Update test data-set (nf-core/test-dataset::bacass ). Two options:
  - Switch from tab to comma separated content/structure on sample sheets for testing (I prefer this one) .
  - Or Change file extensions on sample sheets from csv to tsv
• Add nf-validation on sample sheet

[Daniel-VM]

Validation fails on the sample sheet when attempting to read a tab-separated file with a *.csv extension.

This issue affects all test datasets within nf-core/test-dataset::bacass. It might be advisable to consider changing the file extension from csv to tsv for the test dataset files.

[d4straub]

We could just add the same files with a tsv ending. I think its better to leave the old files in to keep older bacass versions with -profile test running. Do you want to do it or should I?

[Daniel-VM]

Yes!. I agree. I'll do it ;).