Add Zuul configuration to run tests on the CI node

Add Zuul configuration to install Docker on the CI node so we can run
these tests from CI successfully.

Change-Id: I31387d7832d7109f98b51d2958a19e34ade6c420

.zuul.yaml

diff --git a/.zuul.yaml b/.zuul.yaml
new file mode 100644
index 0000000..04cf314
--- /dev/null
+++ b/.zuul.yaml
@@ -0,0 +1,10 @@
+- job:
+    name: plugins-events-build
+    parent: gerrit-plugin-build
+    pre-run:
+        tools/playbooks/install_docker.yaml
+
+- project:
+    check:
+      jobs:
+        - plugins-events-build

tools/playbooks/install_docker.yaml

diff --git a/tools/playbooks/install_docker.yaml b/tools/playbooks/install_docker.yaml
new file mode 100644
index 0000000..89cf315
--- /dev/null
+++ b/tools/playbooks/install_docker.yaml
@@ -0,0 +1,8 @@
+- hosts: all
+  roles:
+    - name: ensure-docker
+  tasks:
+    - name: Install compose
+      shell: |
+        sudo curl -L "https://github.com/docker/compose/releases/download/1.29.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
+        sudo chmod +x /usr/local/bin/docker-compose