Added passing of options to stats ranked and summary.

I'm not super crazy with this implementation but it's the easiest possible way.  Just allow the user to pass in the season via:

`ra.stats.ranked id, season: "SEASON3"`

I would much rather do something like just pass in the season number as an optional param:

`ra.stats.ranked id, 3`

but I'm not sure I like that either.  I'm open to suggestions or just feel free to refactor.

One thing bad is if the user doesn't specify the season name exactly right (SEASON3, SEASON4), Faraday throws a JSON parse error.  So it definitely needs some love.  I'm just not sure what kind of love.