These files are quite large and disk space is limited so make sure we
compress the log files before copying them to storage. Additionally
os-loganalyze will only operate on gzipped log files so this should fix
os-loganalyze with tempest-full job's logs.
This is mostly a check to confirm everything works as expected but we
probably want to move the gzip step into the log publication roles so
that all log files end up compressed.
Change-Id: Ie87962428e0ca755c211cc5e664a14a9f2a79ac4
2700bf88a5