More comprehensive CI testing

[muffato]

Description of feature

In parallel of moving to nf-test (#138) we need to increase the coverage of our CI tests. We've indeed found a couple of bugs on the dev branch that were caused by a lack of testing.

Overall, I'd want to see tested:

1. the default test profile (already the case)
2. pre-computed buscos (already the case)
3. --align
4. fetchngs input samplesheet
5. --mask
6. missing --busco parameter (makes Busco download databases)

We already have individual test profiles for some of those feature, and we could simply write the remaining ones and run them all one by one on GitHub. However it may take a little while to run.

I think that in this particular case we should be able to combine scenarios 2-6 together into a single test profile.

[Quanmat]

Bonjour @muffato ,
My name is Krishay Rathaure and i just Wanted to ask whether this is open to contributors?
If so then can you please assign me. I'd love to explore ways I can contribute.

Thanking you.

[muffato]

Hi @Quanmat . Absolutely ! I've assigned it to you

[Quanmat]

Hello @muffato, I’ve made progress on this in #172 , found some bugs too—happy to get your thoughts on next steps :)