Update to using pike cloud-archive

Now that Pike has been released, switch to using the pike version of
UCA instead of ocata, too.

One reason to do so it that it adds python3-ceph packages, allow to have
progress with the python3 compatibility of the Ceph integration.

Change-Id: I7d95e53892b697c72af75ad0ce7ce2dec6d31fde
1 file changed