Job Type REST API for Timeline Updates

[emimaesmith]

Pain Point? Please describe. The existing APIs are not ideal for the updates required for the Timeline view. A new query and API endpoint should be added to return the information needed for the timeline view. This issue will deal with the request for the Job Type timeline.

Desired Solution

• Add the following REST API endpoint to job-type/urls.py: /job-types/timeline/
• Update the job-type/views.py with a new JobTypeTimelineView -- ListAPIView -- Include parameters for job type ids/names, started/ended dates, ?version numbers?
• Add method under JobType models.py to execute query to retrieve: -- Date (all we care about is day. don't need separated by day/hour) -- count (may need this in the future?) -- job type id -- job type name -- job type version -- job type title
• Add serializer to return timeline information in the following format:

  [{
  'job_type_id': 1, 
  'name': 'job-type-1', 
  'title': 'The title',
  'version': '1.0.0', 
  'results': [
    {'date': '2020-01-01', 'count': 124},
    {'date': '2020-01-03', 'count': 3}...
  ]
  }]