Update default backoff value to 1
Merge pull request #309 from rackerlabs/change-default-backoff

Update default backoff value to 1
Name snapshots based on the type of schedule

Add support for naming images appropriately depending on if
the schedule is for a daily or a weekly snapshot.
Merge pull request #310 from rackerlabs/name-based-on-schedule-type

Name snapshots based on the type of schedule
implements qonos.job.failed notification

- qonos.job.failed notification is sent only if the following criteria
  is satisfied.
  - If the job status is updated to CANCELLED
    OR
  - If the job status is updated to ERROR (AND)
    if the number of retries exceeds the max retry count (OR) if the
     current time exceeds the  hard_timeout.
- qonos.job.failed notification includes the error message to the job
  payload if it is available while updating the job status.
- modified existing tests to test the send qonos.job.failed notification
  scenario.
introduce new job state, HARD_TIMED_OUT.

Currently, when a job hard times out, we do not update the status to
denote that the job has failed and hence there is no way to send a
job.failed notification for hard timed out jobs.
With this patch we introduce a new job state (HARD_TIMED_OUT) and based
on this new job state a job.failed notification is sent for the hard
timed out jobs.

Implementation Details:
- introduce a new job state - HARD_TIMED_OUT
- remove the filter for ignoring the hard_timed_out jobs from db
  call, _job_get_next_by_action
- instead update query criteria to ignore jobs whose status is already
  set to 'HARD_TIMED_OUT'
- implement calls for updating and sending job.failed notification in
  JobProcessor
- include tests for the changes done.