Allow the ! prefix to manifest.version linting

[jfy133]

Problem

The nextflow check against manifest.version doesn't actually stop the pipeline with a helpful error message if a users version doesn't use the specify version unless ! is specified before the >=, as described here: https://www.nextflow.io/docs/latest/config.html?highlight=manifest#nextflow-version

Howeve linting fails if !, is included.

Solution

It would be nice if ! would also be accepted by linting on this line (thanks for @drpatelh for pointing towards it):

tools/nf_core/lint.py

Line 467 in 9e33e7f

if self.config.get('manifest.nextflowVersion', '').strip('"\'').startswith('>='):

(Note: I'm not familar with python and don't have much time atm so not comfortable making a PR myself yet).

Alternative

Current workaround, add the following to main.nf

https://www.nextflow.io/docs/latest/metadata.html#nextflow-metadata

[ewels]

Fixed 🎉