Chipseq:Allow BAM file as input
Chipseq:Allow BAM file as input

ref https://github.com/chapmanb/bcbio-nextgen/issues/1481

thanks @LMannarino @lbeltrame

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