fix typo in slurm cancel state

slurm calls it CANCELLED not CANCELED
use sacct if scontrol couldnt find the job

when a job has been in COMPLETED state for longer than a certain ammount of time,
slurm does not display it in the output of scontrol anymore. Instead it complains:
    slurm_load_jobs error: Invalid job id specified

When this happens, fallback to using sacct which has access to the full history.
Merge pull request #322 from luis-rr/master

slurm get job state