weights as option in group file

[annacuomo]

Updated version of https://github.com/populationgenomics/saige-tenk10k/pull/125 to keep more general: have gamma as an arg such that we can provide a value if we want to include dTSS weights, or none if not.

Ran successfully when

• including weights (default gamma): https://batch.hail.populationgenomics.org.au/batches/483314/jobs/1 (files here: cpg-bioheart-test/saige-qtl/input_files/group_files/v2/chr22)
• excluding weights (setting gamma = none): https://batch.hail.populationgenomics.org.au/batches/483312/jobs/1 (files also here: cpg-bioheart-test/saige-qtl/input_files/group_files/v2/chr22, this time with no_weights in the name)

Additionally, updating variant definition to match format from the SAIGE-QTL example group file, i.e. chrom.pos.ref.alt

[annacuomo]

running in main: https://batch.hail.populationgenomics.org.au/batches/483339/jobs/1

finished, files in cpg-bioheart-main/saige-qtl/bioheart_n990_and_tob_n1055/input_files/group_files/v2/chr22