add unit test job for global-requirements

this ensures that we actually gate on our new tox tests in global
requirements, which ensure that the update.py script correctly
updates the requirements.txt and test-requirements.txt.

Change-Id: I4c863232f71568759fc5ac60aba0c49a6d67db2b

modules/openstack_project/files/jenkins_job_builder/config/projects.yaml

@@ -802,6 +802,17 @@
       - pypi-jobs
 
 
+- project:
+    name: requirements
+    github-org: openstack
+    node: precise
+    tarball-site: tarballs.openstack.org
+    doc-publisher-site: docs.openstack.org
+
+    jobs:
+      - gate-{name}-python27
+
+
 - project:
     name: storyboard
     github-org: openstack-infra

modules/openstack_project/files/zuul/layout.yaml

@@ -1079,8 +1079,10 @@ projects:
   - name: openstack/requirements
     check:
       - gate-requirements-install
+      - gate-requirements-python27
     gate:
       - gate-requirements-install
+      - gate-requirements-python27
     post:
       - post-mirror-python26
       - post-mirror-python27