Output directory flag not behaving as expected

[grosscol]

This call fails:

bin/bitstomach.sh -s ../aspire/aspire-spek.json --data ../aspire/mpog-munged.csv -a ../aspire/annotations.r -o /tmp

This call succeeds:

bin/bitstomach.sh -s ../aspire/aspire-spek.json --data ../aspire/mpog-munged.csv -a ../aspire/annotations.r 

Handling output_dir is unimplemented. Functionality currently exists as specifying outfile which defaults to stdout. Either write and test functionality to handle output dir, or remove entirely, and commit to emitting results soley to stdout.