Fix image build checks missing setuptools

Use apt to install python3-pip, and use pip3 in event system has
both pip2 and pip3 installed. Use apt to install setuptools for
Ansible's consumption.

Change-Id: I3e0656acc41d0b0457bf77b89231fbc2763d698e

playbooks/airship-images-build.yaml

@@ -21,12 +21,15 @@
           - python-docker
           - python3-requests
           - pass
+          - python3-pip
+          - python3-setuptools
         state: present
       become: true
       when: ansible_distribution == 'Debian' or ansible_distribution == 'Ubuntu'
     - name: Install docker pip module
       pip:
         name: docker
+        executable: pip3
     - name: Publish images
       block:
         - make: