update gitignore
update gitignore

add checkpoint ignore

Christensen-Lab-Dartmouth/brca_lowstage_DMGRs,Christensen-Lab-Dartmouth/brca_lowstage_DMGRs,gwaygenomics/brca_lowstage_DMGRs,Christensen-Lab-Dartmouth/brca_lowstage_DMGRs,gwaygenomics/brca_lowstage_DMGRs,gwaygenomics/brca_lowstage_DMGRs