Delete ballroom forgeries

They aren't used and spoil my nice test coverage.
Replace and test deprecated associations in User

Skip creating a fancy association altogether; just use `ARel` to create
a SQL query.
Create `comp_url` and `event_url` functions

They are a generic way to get the URL for a competition using a
particular module.
Add gem `webmock` for HTTP tests

Lets you stub out HTTP requests for testing.
Test `ResultsScrapers` fetch and import

Using WebMock, no actual HTTP requests are issued; the response can be
set in the tests.
Completely cover `Couple` with tests

These are kind of silly, but 100% is 100%...
Use `Scrutineering.place_one_dance`

It simplifies things slightly and improves test coverage.
Replace deprecated `:finder_sql` with `Arel`

The poorly-named `prelim_results` association used the deprecated
`:finder_sql` option to `has_many` to get it to execute custom SQL.
Replacing this with Arel removes the deprecation warning and gives me
warm fuzzy feelings of modernity.
Quiet down RSpec and Coveralls console output.

They both spit out needless info, so quiet them down for less noisy test
runs.
Merge branch 'full-test-coverage'

Well, nearly full test coverage. The tests doesn't yet completely cover
scrutineering (which is somewhat concerning) or the error conditions for
scraping (which is no big deal).