When we deploy the kubernetes using Ubuntu's script.
1. First we set the roles "ai i i" and NUM_MINIONS=3, it runs as expected.
2. Then we change the roles to "a i i" and NUM_MINIONS=2, we found it will not run successfully.
It's because there are history files left on the previous deployment.
This commit will delete the files when stop the cluster.
bb28684f43