Updated to ArgumentParser from OptionParser.  Put some simple checks in

to make sure 2bit file and cgivar file has been provided.

To run:

    python -m file_process.utils.cgivar_to_vcf -i <CGIVARFIL> -r <2BITFILE> [-o <OUTPUTFILE>]

If `-i` or `-r` are not specified, it will spit out an error message and the help screen.