Rather than just test a single specific movement key (in this case "up"), go
with all the affected keys. The cost to doing so is zero and it means we get
a full coverage of testing for all the keys that have become a problem with
0.6.0.
Up until now there doesn't seem to have been any unit tests aimed squarely
at setting up bindings, as part of a running application, which are only
about testing the bindings. As such there was no way of slotting in tests
for how inheritance of bindings works.
This starts that process with a view to testing how inheriting
likely *should* work.
See #1343 for some background to this.
