Remove deprecated dev-requirements support.
Remove deprecated dev-requirements support.

Change-Id: I8ae1eeb4daa25715ff02187e3e4c34a3d1c883a4

openstack-infra/project-config,coolsvap/project-config,noorul/os-project-config,openstack-infra/project-config,Tesora/tesora-project-config,dongwenjuan/project-config,dongwenjuan/project-config,anbangr/osci-project-config,coolsvap/project-config,noorul/os-project-config,Tesora/tesora-project-config,anbangr/osci-project-config