scheduler: Change test to exercise code path where nodes are created later
scheduler: Change test to exercise code path where nodes are created later

Signed-off-by: Aaron Lehmann <8ecfc6017a87905413dcd7d63696a2a4c351b604@docker.com>

jlhawn/swarmkit,jlhawn/swarmkit,AliyunContainerService/swarmkit,sungwonh/swarmkit,Noyan759/swarmkit,Noyan759/swarmkit,RenaudWasTaken/swarmkit,docker/swarmkit,docker/swarmkit,dperny/swarmkit-1,cheyang/swarmkit,dperny/swarmkit-1,cheyang/swarmkit,alyyousuf7/swarmkit,RenaudWasTaken/swarmkit,alyyousuf7/swarmkit,sungwonh/swarmkit,AliyunContainerService/swarmkit