Create pipeline, job template and test WIP check

Create a pr-status pipeline that runs on PR changes (including
labeling/unlabeling). Define a kata-pre-checks job template that
runs the kata-github-wip job on that pipeline.

Apply that template to the kata-containers/proxy GitHub repository
for testing.

Depends-On: https://review.openstack.org/634248
Change-Id: I67eb5db8cee02069b1813642f40254420d41075f

zuul.d/pipelines.yaml

@@ -100,3 +100,37 @@
       mysql:
     window-floor: 20
     window-increase-factor: 2
+
+- pipeline:
+    name: pr-status
+    description: |
+      New PRs, modified PRs and re-labelled PRs enter this pipeline to
+      have their merge-readiness status reevaluated.
+    success-message: PR is ready to merge.
+    failure-message: PR merging is blocked by a WIP label or title keyword.
+    manager: independent
+    precedence: low
+    trigger:
+      github:
+        - event: pull_request
+          action:
+            - opened
+            - changed
+            - reopened
+            - labeled
+            - unlabeled
+    start:
+      github:
+        status: pending
+        comment: false
+    success:
+      github:
+        status: 'success'
+      mysql:
+    failure:
+      github:
+        status: 'failure'
+      mysql:
+    # Don't report merge-failures to github
+    merge-failure:
+      mysql:

zuul.d/project-templates.yaml

@@ -0,0 +1,8 @@
+- project-template:
+    name: kata-pre-checks
+    description: |
+      This template contains pre-check tests for Kata containers
+      repositories.
+    pr-status:
+      jobs:
+        - kata-github-wip

zuul.d/projects.yaml

@@ -9,3 +9,8 @@
     gate:
       jobs:
         - kata-zuul-jobs-linters
+
+- project:
+    name: kata-containers/proxy
+    templates:
+      - kata-pre-checks