Remove all routes but competition and events

They are unused anyway, since nobody would want to display a single mark
by itself.
Expect visiting pages to succeed in tests.

It is unlikely that the rest of the test would succeed if a non-200
status code was returned, but always nice to test it explicitly.
Remove unused controllers, views, and specs.

The only routes which remain are "/competitions", "/competitions/:id",
and "/competitions/:id/events/:number", so all other controllers and
views can be deleted.
Create specs for views helpers.

This should round out specs for functionality not covered by features.
Fix issue with leaking `Couple`s in spec

Apparently, `before(:all)` blocks in Rspec do not get automatically
cleaned by the `database_cleaner` gem, so the competition has to be
destroyed manually in an `after(:all)` block.

By checking explicitly against the `Event` ID, this can be mitigated.
Run all specs in CI, now that unused ones are gone

All specs should be passing now, so do not restrict CI builds to just
the model specs.
Merge branch 'remove-unused-views-and-routes'