UMI: ensure umi_bam set for non-paired analyses
UMI: ensure umi_bam set for non-paired analyses

biocyberman/bcbio-nextgen,biocyberman/bcbio-nextgen,vladsaveliev/bcbio-nextgen,a113n/bcbio-nextgen,vladsaveliev/bcbio-nextgen,lbeltrame/bcbio-nextgen,a113n/bcbio-nextgen,brainstorm/bcbio-nextgen,vladsaveliev/bcbio-nextgen,biocyberman/bcbio-nextgen,lbeltrame/bcbio-nextgen,chapmanb/bcbio-nextgen,a113n/bcbio-nextgen,brainstorm/bcbio-nextgen,chapmanb/bcbio-nextgen,brainstorm/bcbio-nextgen,chapmanb/bcbio-nextgen,lbeltrame/bcbio-nextgen