Add bowtie2 back into the custom installer.
Add bowtie2 back into the custom installer.

Previous commit just disabled homebrew installation of bowtie2.

averagehat/cloudbiolinux,AICIDNN/cloudbiolinux,pjotrp/cloudbiolinux,elkingtonmcb/cloudbiolinux,rchekaluk/cloudbiolinux,joemphilips/cloudbiolinux,elkingtonmcb/cloudbiolinux,AICIDNN/cloudbiolinux,heuermh/cloudbiolinux,heuermh/cloudbiolinux,chapmanb/cloudbiolinux,elkingtonmcb/cloudbiolinux,kdaily/cloudbiolinux,lpantano/cloudbiolinux,pjotrp/cloudbiolinux,averagehat/cloudbiolinux,heuermh/cloudbiolinux,elkingtonmcb/cloudbiolinux,joemphilips/cloudbiolinux,averagehat/cloudbiolinux,lpantano/cloudbiolinux,joemphilips/cloudbiolinux,chapmanb/cloudbiolinux,heuermh/cloudbiolinux,kdaily/cloudbiolinux,pjotrp/cloudbiolinux,rchekaluk/cloudbiolinux,kdaily/cloudbiolinux,chapmanb/cloudbiolinux,rchekaluk/cloudbiolinux,joemphilips/cloudbiolinux,kdaily/cloudbiolinux,averagehat/cloudbiolinux,AICIDNN/cloudbiolinux,chapmanb/cloudbiolinux,lpantano/cloudbiolinux,pjotrp/cloudbiolinux,rchekaluk/cloudbiolinux,AICIDNN/cloudbiolinux