Following the [current test suite](https://github.com/exercism/x-common/blob/aa12f2e403270854e709b20a2aa62cf24e60d171/exercises/luhn/canonical-data.json) implement the [luhn exercise](https://github.com/exercism/x-common/tree/aa12f2e403270854e709b20a2aa62cf24e60d171/exercises/luhn)
Following the current test suite implement the luhn exercise