Change parallel processing for assemble_reads.py
Change parallel processing for assemble_reads.py

The previous version of this script would create cores*cores and cores*memory demands on the system. This change adds an argument `--instances` that hopefully makes this more explicit.
AntonelliLab/seqcap_processor,AntonelliLab/seqcap_processor,AntonelliLab/seqcap_processor,AntonelliLab/seqcap_processor