We hit Ansible rc -13 again in gate testing for a system-config change.
This is the error code that Ansible returns for a task when it tries to
connect via ssh as the ControlMaster is shutting down due to the
ControlPerist timeout being reached. We already set ControlPersist to
180 seconds in an effort to make this an uncommon issue. Set
ServerAliveInterval to 60 seconds to match zuul's configuration for
Ansible as that seems to work well for Zuul jobs.
Change-Id: I66f28fcf7f539b76bfbb6da99c9836a6a92431e5
ef35694661