title: Mutations - batch creation of objects
body: <p>I want to use graphene to create many people in one go.
  The document only mention the way to create one person like this:</p>
  
  <pre><code>class CreatePerson(graphene.Mutation):
  class Input:
      name = graphene.String()
      age = graphene.Int()
  
  ok = graphene.Boolean()
  person = graphene.Field(lambda: Person)
  
  @staticmethod
  def mutate(root, args, context, info):
      person = Person(name=args.get('name'), age=args.get('age'), mobile=args.get('mobile'))
      ok = True
      return CreatePerson(person=person, ok=ok)
  </code></pre>
  
  <p>are there any ways to get it done?</p>