Run one sbws main loop using the test network as part of integration tests

Currently is not possible to run the main sbws scanner function run_speedtest because it uses threads, which doesn't work with pytest. The threads could be mocked or run one single process, but behaviour would be different as with threads. Since integration tests launch a testing network, it's possible to just run sbws configured to run that network. It's also possible to make sbws stops after the first loop when being in a testing network so that it doesn't run forever. While this won't behave the same way as in a public network, it might still help to find bugs.