* First step into creating a seqtk/mergepe module to interleave fastQ input
* First rewrite of main.nf to make the module perform the desired (interleave/merge of pe reads) task
* Modifications to test the new seqtk/mergepe module.
* Improving the seqtk/mergepe module to output single end reads as well, and making sure tests work
* Modified so that gzip uses -n and that single read entries are symlinked with ln -s instead of copied, therefore updated test.yml as well.
* Fix trailing whitespaces
Co-authored-by: Daniel Lundin <daniel.lundin@lnu.se>