APPS-1450 suppress nextflow help (#859)
APPS-1450 suppress nextflow help (#859)

* APPS-1450 - supressed Nextflow help messages
dnanexus/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit,dnanexus/dx-toolkit