0.2.0

Dev update april 24 (#3)

* change of output name of merged plink2 sumstats

* plink2 now not longer uses sexinfo from the input fam file but requires a column for that in the covar file, bringing it in line with the rest of the assoc tools

* implementing categorical covars

* plink2 update

* Add pruned paramter to documentation

* added bcftools filter, smaller adjustments