Turn ObservationControllerTest green
Turn ObservationControllerTest green

Fixed tests by one of these procedures:
- Added `login` to login someone before any GET
- Adjusted assertions
- In `test_show_observation_specimen_stuff` removed a bund of assertions that no longer made sense.
They all tested show_observation view with nobody logged in.
But that cannot happen anonymous users can no longer  view observations
.

MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer