gzip the ARA report after generating it
gzip the ARA report after generating it

ARA behaves well gzipped and shaves a lot of the size due to it being
composed mostly of text.

Change-Id: I7a3f21af365d13ba783d200a75d18b50429a1488

dardelean/kolla-ansible,dardelean/kolla-ansible,dardelean/kolla-ansible