Avoid use of exit-statements

[asp8200]

Description of feature

(Not sure if this should be a feature-issue or bug-issue, anyways here goes...)

Version 3.0.2 of Sarek contains a bunch of exit-statement. Here is an example:

sarek/workflows/sarek.nf

Line 74 in bcd7bf9

exit 1

I recently learned from Marcel Ribeiro-Dantas (@mribeirodantas) that those exit-statements should probably be replaced by exceptions like, say,

throw new Exception("Bad stuff happend")

since "if Nextflow is running in a subprocess of something else, it [an exit-statement] kills the entire thing".

What do you say we replace the exit-statements with exceptions?

[maxulysse]

cf nf-core/rnaseq#978