Synchronize src repos to workspace directory

And support Depends-On for zuul/nodepool/shade/diskimage-builder/gear.

Change-Id: I48868555e0358bc13b9ece56d19926805eae230a
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

.zuul.d/jobs.yaml

@@ -41,6 +41,15 @@
       - openstack-infra/nodepool
       - openstack-infra/shade
       - openstack-infra/zuul
+    vars:
+      # NOTE(pabelanger): Because we want to test Depends-On patches in the
+      # gate, we don't want our roles to update git after we pushed the repos
+      # from zuul-executors.
+      diskimage_builder_git_update: false
+      gear_git_update: false
+      nodepool_git_update: false
+      shade_git_update: false
+      zuul_git_update: false
 
 - job:
     name: windmill-centos-7

tests/base-minimal.yaml

@@ -8,6 +8,12 @@
       set_apt_mirrors_trusted: True
 
   tasks:
+    - name: Synchronize src repos to workspace directory.
+      synchronize:
+        dest: .
+        src: "{{ zuul.executor.src_root }}"
+      no_log: true
+
     # NOTE(pabelanger): Because use-cache-repos force the delete of origin, the
     # git module from ansible will not setup origin correctly. This is like a
     # bug in ansible, and should be discussed upstream.