Add samtools as a resource requirement to the RNA-seq aligner
Add samtools as a resource requirement to the RNA-seq aligner

Fixes #1006 but only in technicality, the issue of not scaling
automatically during streaming still exists, but has an
easy workaround. Thanks to @schlelhorn for the suggestion.

brainstorm/bcbio-nextgen,lbeltrame/bcbio-nextgen,biocyberman/bcbio-nextgen,guillermo-carrasco/bcbio-nextgen,a113n/bcbio-nextgen,lpantano/bcbio-nextgen,lpantano/bcbio-nextgen,gifford-lab/bcbio-nextgen,guillermo-carrasco/bcbio-nextgen,Cyberbio-Lab/bcbio-nextgen,mjafin/bcbio-nextgen,brainstorm/bcbio-nextgen,chapmanb/bcbio-nextgen,chapmanb/bcbio-nextgen,biocyberman/bcbio-nextgen,elkingtonmcb/bcbio-nextgen,elkingtonmcb/bcbio-nextgen,lpantano/bcbio-nextgen,vladsaveliev/bcbio-nextgen,mjafin/bcbio-nextgen,mjafin/bcbio-nextgen,lbeltrame/bcbio-nextgen,lbeltrame/bcbio-nextgen,Cyberbio-Lab/bcbio-nextgen,brainstorm/bcbio-nextgen,guillermo-carrasco/bcbio-nextgen,vladsaveliev/bcbio-nextgen,gifford-lab/bcbio-nextgen,a113n/bcbio-nextgen,a113n/bcbio-nextgen,elkingtonmcb/bcbio-nextgen,gifford-lab/bcbio-nextgen,vladsaveliev/bcbio-nextgen,Cyberbio-Lab/bcbio-nextgen,chapmanb/bcbio-nextgen,biocyberman/bcbio-nextgen