Fix STATIC_ROOT warnings in tests
Fix STATIC_ROOT warnings in tests

The tests warn about a missing directory when the STATIC_ROOT points at a
directory that doesn't exist. The correct thing would probably be to have
it point to something that actually exists rather than creating an empty
directory to silence it.

HelsinkiHacklab/asylum,HelsinkiHacklab/asylum,HelsinkiHacklab/asylum,HelsinkiHacklab/asylum