title: running flow through code Django-Viewflow
body: <p>I want to run my process entirely by code. I've managed to start a process but a I can't run the next part of the process. I tried using the "flow.Function" and calling my desired function but i't says</p>
  
  <pre><code>'Function {} should be called with task instance', 'execute'" 
  </code></pre>
  
  <p>and the documentation on this subject is'nt very clear.</p>
  
  <p>flows.py</p>
  
  <pre><code>@flow.flow_start_func
  def create_flow(activation, campos_proceso, **kwargs):
      activation.process.asignador = campos_proceso['asignador']
      activation.process.ejecutor = campos_proceso['ejecutor']
      activation.process.tipo_de_flujo = campos_proceso['tipo_de_flujo']
      activation.process.estado_del_entregable = campos_proceso[
      'estado_del_entregable']
      activation.process.save()
      activation.prepare()
      activation.done()
      return activation
  
  @flow.flow_func
  def exec_flow(activation, process_fields, **kwargs):
      activation.process.revisor = process_fields['revisor']
      activation.process.save()
      activation.prepare()
      activation.done()
      return activation
  
  @frontend.register
  class Delivery_flow(Flow):
      process_class = DeliveryProcess
      start = flow.StartFunction(create_flow).Next(this.execute)
      execute = flow.Function(exec_flow).Next(this.end)
      end = flow.End()
  </code></pre>
  
  <p>views.py </p>
  
  <pre><code>def Execute(request): #campos_ejecucion, request):
      campos_ejecucion = {
      'ejecutor':request.user,
      'revisor':request.user,
      'observaciones_ejecutor':'Este es un puente magico',
      'url_ejecucion':'https://www.youtube.com/watch?v=G-yNGb0Q91Y',
      }
      campos_proceso = {
      'revisor':campos_ejecucion['revisor']
      }
  
      flows.Delivery_flow.execute.run()
      Entregable.objects.crear_entregable()
      return render(request, "Flujo/landing.html")
  </code></pre>