Updated Response codes for job create and delete

* Response, with appropriate error codes, is handled by job.py
functions for create and delete requests.
* Updated cluster.delete() to return True in case of a successful
termination.

Signed-off-by: Shashank Sahni <shredder12@gmail.com>
Updated job_test to show headers during output

Added '-i' option in all curl requests to show HTTP headers during
output.

Signed-off-by: Shashank Sahni <shredder12@gmail.com>