adds missing $self to read_regions call#1

jrandall wants to merge 1 commit intoVertebrateResequencing:masterVertebrateResequencing/vr-runner:masterfrom

wtsi-hgi:fix/run-bt-mpileup-read-regionswtsi-hgi/vr-runner:fix/run-bt-mpileup-read-regionsCopy head branch name to clipboard