The tempest-plugin-cookiecutter repo was created under the openstack
namespace instead of openstack-dev. This commit just updates the path
in projects.yaml to reflect reality.
Change-Id: I8b3ee307d1565b615e1f76f997edd60ff41c28d7
Depends-On: Ieb97af5837888ba4b0aab4d7dda37e7796f9f0f0