Forward arguments to `go test` in `bin/run-test`

See merge request !5

To enable race detection (`-race`) or run only specific tests (`-run $test`), it's useful to pass extra arguments to `go test`. Currently this means we must choose between filtering out noise and controlling how the tests are run. This change makes `bin/run-test` forward its arguments (if any) on to `go test`, giving the best of both worlds.

`$@` is the safe way to [forward script arguments](https://www.gnu.org/software/bash/manual/html_node/Special-Parameters.html); it is equivalent to `"$1" "$2" "$3"` and so on.