The way we have it set up, Simplecov generates a report in Codecov's format
and tries to send it to them, which fails.
This gets us back to the former Simplecov setup. This lets you check the
visual coverage report navigating to `coverage/index.html`.
We will almost certainly *never* invest the required amount of dev time to cover all this non-critical code with tests, so we may as well drop it from the report.
The configuration can go into the central .simplecov file and then we
just need to `require` simplecov to start the coverage process. This
also avoids duplicating the config if we want to start simplecov from
the rails server to cover the lines used in by the server in feature
specs.
https://github.com/simplecov-ruby/simplecov#using-simplecov-for-centralized-config
