Put back Rails specific config for SimpleCov (#389)
Put back Rails specific config for SimpleCov (#389)

Without the `'rails'`, coverage drops to ~15% for the legacy tests, which probably means, it doesn't find all the tests.
openSNP/snpr,philippbayer/snpr,philippbayer/snpr,philippbayer/snpr,openSNP/snpr,philippbayer/snpr,openSNP/snpr,openSNP/snpr