Limit conductor to 5 workers

We don't actually use conductor right now, but we shouldn't need more
than 5 when we start using it. We can scale up as needed, this gets us
below the alerting threshold.
Limit glance-registry workers to 5

We don't typically need more, can be overridden by environment. Quells
sensu alerts.
Set keystone public/admin wokers to 5 by default

Clears monitoring, can be overridden.
Limit cinder api to 5 workers by default.