Use gatk's farm to convert vcf2fasta

## Background

It will be easier to understand a distance calculation when applying it to the difference between two fasta files (rather than between two vcf files). It will also be easier to label a fasta files with secondary attributes (e.g. CDS regions)

## Aim

Create a script that converts a vcf file to a fasta file. Use gatk's fastaalternatereferencemaker (farm) module to perform this action.