TimoutException Test: a mozhttpd subclass with a delayed HTTP response and unittest

[Nebelhom]

This issue can only be worked on once this pull request is landed.

In order to write a test for the TimeoutException in the scraper class, we would ideally need a mock server that can give a delayed HTTP response. We are using mozhttpd as our mock server, so presumably a subclass of the RequestHandler is needed, but I think this is open for discussion.

Best check the source of mozhttpd and also the discussion in the mentioned PR for more information and ideas.