Do the sdist check in a virtualenv
Do the sdist check in a virtualenv

We trigger easy_install if we don't do this, which is not the point of
the test.

Change-Id: Iedd79d59ce0134017d9961fbe316babaee04e72f

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