docs: def worker(namespace, name, branch='master'):
      '''The simple_ci background worker process'''
      with repository(namespace, name, branch) as (path, latest, cache):
          if cache.get(latest, None) and json.loads(cache[latest])['status'] != 'starting':
              return 'Build already started'
  
          data = {'status': 'in_progress', 'result': ''}
          cache[latest] = json.dumps(data)
          test_output = tox(_iter=True)
          try:
              for line in test_output:
                  data['result'] += line
                  cache[latest] = json.dumps(data)
              data['build_success'] = True
          except Exception:
              data['build_success'] = False
          data['status'] = 'complete'
          cache[latest] = json.dumps(data)
          return 'Build successfully completed'