jobs.exit_success allow to check if a job has executed and exit successfully

[meaksh]

What does this PR do?

This PR create a new method for runners.jobs which easy allow you to check if a job has been executed and it has returned successfully.

Currently salt lets you check the results of a job using:

# salt-run jobs.lookup_jid 20160520173111930120
minionsles12sp1-suma3pg.vagrant.local:
    ----------
    pid:
        15124
    retcode:
        0
    stderr:
    stdout:

If what we want is to check if a job has executed and returned successfully or not, I propose jobs.exit_success on this PR:

# salt-run jobs.exit_success 20160520173111930120
minionsles12sp1-suma3pg.vagrant.local:
    True

What do you think?

Tests written?

No

[cachedout]

I like the idea here but it looks like a lot of this code is copied directly from lookup_jid. Can we just call to that and then parse the results in this function? I don't like to have this much duplicated code in a runner if it can be helped. Let me know what you think.

[meaksh]

I'm agree with you @cachedout , parse the results of lookup_jid is better than duplicate code.
In our case, exit_success only uses data contained in the results of lookup_jid, so I added a refactor of exit_success in order to parse the results of lookup_jid.

What do you think now?

[cachedout]

Much nicer! Thanks, @meaksh !