Quick patch for ranger image publish gate

Ranger-agent image publish gate
requires the python docker package,
this patch adds it back

Change-Id: I20058c5df33b029e4dd14219f3d2480599063ba4

tools/zuul/playbooks/docker-image-build.yaml

@@ -8,6 +8,9 @@
     - name: Make images
       when: not publish
       block:
+        - pip:
+            name: docker
+            version: 2.7.0
         - make:
             chdir: "{{ zuul.project.src_dir }}"
             target: images
@@ -25,6 +28,9 @@
 
     - name: Publish images
       block:
+        - pip:
+            name: docker
+            version: 2.7.0
         - docker_login:
             username: "{{ ranger_agent_quay_io_credentials.username }}"
             password: "{{ ranger_agent_quay_io_credentials.password }}"