Shift docker and pip setup to pre-playbook for quick-start

Installing docker and pip are pre-reqs and we're using zuul roles
to do them, so they're not really testing explicit quick-start
steps. Move them to pre-run.

Change-Id: I374dac18b9b7e376d924b11f4661355ea7c4d149

.zuul.yaml

@@ -120,6 +120,7 @@
     name: zuul-quick-start
     parent: opendev-buildset-registry-consumer
     description: Run the commands in the Zuul quick-start documentation.
+    pre-run: playbooks/quick-start/pre.yaml
     run: playbooks/quick-start/run.yaml
     post-run: playbooks/quick-start/post.yaml
     required-projects:

playbooks/quick-start/pre.yaml

@@ -0,0 +1,7 @@
+- hosts: all
+  roles:
+    - ensure-pip
+    - name: ensure-docker
+      use_upstream_docker: false
+      docker_compose_install: true
+    - use-buildset-registry

playbooks/quick-start/run.yaml

@@ -2,12 +2,6 @@
   vars:
     workspace: /tmp/quickstart-test
     local: false
-  roles:
-    - name: ensure-docker
-      use_upstream_docker: false
-      docker_compose_install: true
-    - ensure-pip
-    - use-buildset-registry
   tasks:
     - name: Install git-review
       command: python3 -m pip install git-review