add zuul-cloner location to $PATH
add zuul-cloner location to $PATH

We still run some of the release tools by hand, and the dev systems
where we do that do not have zuul-cloner installed to the same location
as on the CI nodes. Add the CI location to the shell's path instead of
invoking zuul-cloner using the full path explicitly.

Change-Id: I9a87e3e7873ea00fc738cc2a21a26cca2ff49fab
Signed-off-by: Doug Hellmann <0798ebecfb7bc4dfb9d0445c2fa030eb64e1fa1c@doughellmann.com>

Tesora/tesora-project-config,openstack-infra/project-config,Tesora/tesora-project-config,openstack-infra/project-config