Removed Champion name from Ranked stats

The champion name is removed because the version was not localized.
Champion name can be retrieved from static data API

From Riot announcement,
>This API removes the non-localized, internal champion name that was
>being returned in the ChampionStatsDto for the
>/api/lol/{region}/v1.3/stats/by-summoner/{summonerId}/ranked endpoint.

Related to #24