Fix upstart stop

The generated upstart script doesn't always stop correctly the running child (or grandchild) process.
For example, this is how the process tree looks like when the process is running:

    [deploy@nko ~]$ ps -ef | grep consumer
    root      4377     1  ?        su - deploy -c cd /home/deploy/kapara/releases/20131230141943; export PORT=5000; bin/kapara consumer >> /home/deploy/kapara/shared/log/consumer-1.log 2>&1
    deploy    4381  4377  ?        -bash -c cd /home/deploy/kapara/releases/20131230141943; export PORT=5000; bin/kapara consumer >> /home/deploy/kapara/shared/log/consumer-1.log 2>&1
    deploy    4497  4381  ?        ruby bin/kapara consumer

And this is how it looks like after the stop command:

    [deploy@nko ~]$ ps -ef | grep consumer
    deploy    4497  1  ?        ruby bin/kapara consumer

This issue was actually fixed in [pull request #137](https://github.com/ddollar/foreman/pull/137), but for some reason I can't see the fix line in the code.