Swap out log.Fatal in executeAndWait for return code
Swap out log.Fatal in executeAndWait for return code

Under normal circumstances we should only reach the replaced line if the
path to the user-defined executable is misconfigured. But if there's some
other problem with the underlying OS like a disk error then it's possible
to reach it, so we'll rely on the lack of heartbeat to tell us something
went wrong rather than intentionally crash.

justenwalker/containerbuddy,benoittoulme/containerpilot,justenwalker/containerpilot,flyinprogrammer/containerpilot,flyinprogrammer/containerpilot,joyent/containerbuddy,joyent/containerpilot,benoittoulme/containerpilot,tgross/containerbuddy,benoittoulme/containerpilot,justenwalker/containerbuddy,joyent/containerbuddy,joyent/containerpilot,tgross/containerbuddy,joyent/containerpilot,justenwalker/containerpilot