Right now autotest priorities are not chosen not well:

Priority = enum.Enum('Weekly', 'Daily', 'PostBuild', 'Default', 'Build',
                     'PFQ', 'CQ', 'Super',  start_value=10, step=10)

Proposal:
1) Weekly should be higher than Daily, to encourage people have an incentive to use less resources.
2) Same for PostBuild (perbuild), it should be lowest in this list.
3) We need a new priority for test_that :lab:, right now it is 'Default'. I think it should be either lowest or below Daily, as otherwise people starve pools.

In other words we should end up with something like:

Priority = enum.Enum('PostBuild', 'TestThat', 'Daily', 'Weekly', 'Default', 'Build',
                     'PFQ', 'CQ', 'Super')