text: Title: Schema default value not used
  Body: Trying to set a default value for a Schema inside of a Parameter. It does not seem to be getting picked up in Swagger when I use the "Try it out" functionality.
  
  My schema looks like this:
  
  ```
      @swagger_auto_schema(
              operation_id="Get a mission plan",
              responses={
                  200: 'test'},
              manual_parameters=[
                  openapi.Parameter(
                      name='Organization',
                      in_=openapi.IN_HEADER,
                      description="Organization name",
                      required=True,
                      schema=openapi.Schema(
                          type=openapi.TYPE_STRING,
                          default="Organization 1",
                      )
                  )
              ]
          )
  ```
  
  Perhaps providing a more in depth example in testproj, that uses more of the OpenApi parameters, would be helpful. From what I read [here](https://swagger.io/docs/specification/adding-examples/) it seems the example field should be used rather than default, but it does not seem to be an available field in the Schema class?