Fix clean target
Fix clean target

annkupi/picard,nh13/picard,broadinstitute/picard,nh13/picard,alecw/picard,annkupi/picard,nh13/picard,broadinstitute/picard,broadinstitute/picard,broadinstitute/picard,broadinstitute/picard,alecw/picard,alecw/picard,nh13/picard,annkupi/picard,alecw/picard,annkupi/picard