Pass ZUUL_* env vars through tox
Pass ZUUL_* env vars through tox

So that zuul-cloner inside of a tox env works

Change-Id: I5d7428be62fccf0d28d5d39dafdc58193e7f9ad6

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