Return NoContent when mocking HTTP 204 operations

[julienschuermans]

There's never a need to return a response for HTTP 204 - and these code are unlikely to have any "example" response documented in the spec.

Avoids a uvicorn RuntimeError "Response content longer than Content-Length" when mocking a (3.0) spec containing:

...
      responses:
        '204':
          description: No Content
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ProblemDetails'
...

• We could also move this if/else check into the operation's example_response method. Thoughts?

[coveralls]

coverage: 94.388% (-0.02%) from 94.408%
when pulling 0e626b3 on julienschuermans:patch-1
into 3450a60 on spec-first:main.

[chrisinmtown]

I guess you'll have to add/extend a test case to cover the newly added lines?

[julienschuermans]

I guess you'll have to add/extend a test case to cover the newly added lines?

I can do that - not sure where to place this though. In test_mock.py, test_mock2.py or test_mock3.py ? I guess we want to test behaviour for both Swagger 2.0 and OpenAPI 3? @RobbeSneyders do you have any input?