Add CRASS

[dcdanko]

CRASS Finds CRISPR spacers and inserts

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3664793/
https://github.com/ctskennerton/Crass

[dcdanko]

This module is being moved to v1.1.0 (#12) since this software requires tricky dependency management to install.