* split apart dependencies of vaccine peptide selection
* added unit tests forvaccine
* peptide sorting by four criteria (mutant epitope score, negative wildtype epitope score, number mutated residues, distance from the center)
* print and write FASTA of vaccine peptides with a little mutation metadata
more unit tests for vaccine peptide selection, fixed IEDB MHC binding predictor
Merge pull request #164 from hammerlab/vaccine_peptide_ranking_and_output

split apart dependencies of vaccine peptide selection