Add a focal test

This adds a boot test for the newly released Ubuntu Focal release.

Depends-On: https://review.opendev.org/722556
Change-Id: If8976a3f99a02c8d85cd3818d8c77c75b60816d8

.zuul.d/jobs.yaml

@@ -304,6 +304,23 @@
           DIB_DISABLE_APT_CLEANUP: '1'
           DIB_DEBOOTSTRAP_EXTRA_ARGS: '--no-check-gpg'
 
+- job:
+    name: dib-nodepool-functional-openstack-ubuntu-focal-src
+    description: |
+      Test building and booting an Ubuntu focal image with Nodepool
+      and OpenStack
+    parent: dib-nodepool-functional-src-base
+    pre-run: playbooks/dib-nodepool/debootstrap.yaml
+    vars:
+      nodepool_diskimage:
+        base_element: ubuntu-minimal
+        release: 'focal'
+        mirror: "http://{{ zuul_site_mirror_fqdn }}/ubuntu"
+        env-vars:
+          DIB_APT_LOCAL_CACHE: '0'
+          DIB_DISABLE_APT_CLEANUP: '1'
+          DIB_DEBOOTSTRAP_EXTRA_ARGS: '--no-check-gpg'
+
 - job:
     name: dib-nodepool-functional-openstack-gentoo-src
     description: |

.zuul.d/project.yaml

@@ -17,6 +17,7 @@
         - dib-nodepool-functional-openstack-fedora-31-src
         - dib-nodepool-functional-openstack-ubuntu-xenial-src
         - dib-nodepool-functional-openstack-ubuntu-bionic-src
+        - dib-nodepool-functional-openstack-ubuntu-focal-src
         # NOTE(ianw): 2020-04-22 these have been out of the gate for a
         # while; promote to voting after some stability.
         - dib-nodepool-functional-openstack-opensuse-15-src:
@@ -59,6 +60,7 @@
         - dib-nodepool-functional-openstack-fedora-31-src
         - dib-nodepool-functional-openstack-ubuntu-xenial-src
         - dib-nodepool-functional-openstack-ubuntu-bionic-src
+        - dib-nodepool-functional-openstack-ubuntu-focal-src
         - dib-functests-xenial-python3
         - dib-functests-centos7-python2
         - dib-functests-bionic-python3