Since there is no central storage for the restart actions and the tests
at the moment, they should have timestamped output to correlate events.
Using a standard format will make this easier to do programmatically,
too.
The output is sent both to stdout and a log file. Additionally, Ansible
output is suppressed now, so it doesn't pollute the console. Log times
are in UTC, to avoid timezone mismatches between nodes (observed in
multi-node AIOs).
The `configure_logging` function was copied into the tests/keystone.py
file instead of put into a common module in order to keep that file a
standalone unit for the time being.
Change-Id: I399d1827a8559896ca87e45c00241293ccd033d2
c2aeb03b10