Add jenkins01 and jenkins02, both of which will have unit test and
devstack slaves. Leave jenkins.o.o alone; over time it will be
reduced so that it alone has special jobs and privileged slaves
attached to it.
Note that currently all of the jobs will be defined on all nodes,
including jobs on timers. I think the long-term fix for that is to
have zuul schedule timed jobs.
Change-Id: I10bbd5555e5194b1031700975d5b3ae6b458b8b3