Add diskcache to Cockpit dashboard requirements
Add diskcache to Cockpit dashboard requirements

When we started to use diskcache it needs to be installed before

Change-Id: Ibc43fdd5c75e6d62ae825b8ff83429416f9b4860

redhat-openstack/rdo-infra,rdo-infra/ci-config,rdo-infra/ci-config,redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,rdo-infra/ci-config,rdo-infra/ci-config