Remove virtualenv-tools in the examples.
Remove virtualenv-tools in the examples.

We shouldn't use virtualenv-tools, and it shouldn't appear
in our documentation.

Change-Id: I98d4ac05fa303cad4069c9939a251b07a154286e
Partial-Bug: #1741634

stackforge/os-ansible-deployment,bunchc/openstack-ansible,openstack/openstack-ansible,bunchc/openstack-ansible,stackforge/os-ansible-deployment,openstack/openstack-ansible