Jomrungandr: change default authentication behavior

there were a problem in the tests if no token were provided
Jormungadr: better stat test behavior

we did not check that the mock method was called, so the tests were
useless.

We'll need to replace that with real mock soon!
Jormungadr: best filtering handling

it is now possible to test the best journey
Jormungandr: add additional tests
Jormungandr: change stat saving mode to work in jenkins
Merge pull request #403 from antoine-de/best_filtering

Best filtering