Add loader status details options to %load_ids

[michaelnchin]

Issue #, if available: #350

Description of changes:

• Added --details option to %load_ids. This displays a table containing status and other details for each bulk load job, as available via the Neptune Load Get-Status API.
• Added --limit option to %load_ids. When used, the details view will be restricted to only display the statuses for the X most recent bulk load jobs submitted.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[triggan]

@michaelnchin - I tested this against a few scenarios and noticed an error when the magic encountered a load with a LOAD_IN_QUEUE status. The error was:

{'error': KeyError('feedCount')}

It appears that the fields that are returned as part of the load status API call are not always included depending on the job status. So feedCount in particular is not returned for a queued job. I don't know what may be different of jobs with other kinds of status.

[michaelnchin]

Thanks for the catch, @triggan. I've added a check for the presence of the feedCount object in each load status response.

[triggan]

LGTM!