1.5.4

This is a hotfix release. It fixes the following issues:

• The pvacseq generate_protein_fasta command would previously error out when running with a selected peptide_sequence_length that would reduce in peptides < 7 amino acids long. This error would occur when calculating manufacturability metrics. This release now only calculates these metrics for peptides >=7 amino acids long.
• We updated the calculation for the flanking sequence length when generating peptide sequences to result in peptides that are closer in length to the requested peptide_sequence_length.
• This release fixes an edge case where a frameshift mutation impacted the first amino acid of a transcript. This case would previously throw a fatal error but will now be processed as expected.