Game Key redemption

[saitho]

I noticed that it is now possible to redeem the game keys via the web interface:
https://store.steampowered.com/account/registerkey

Redeeming a key sends a POST request to the URL https://store.steampowered.com/account/ajaxregisterkey/ with the parameters product_key and sessionid. I saw that there was a sessionid that is used in this package.
Maybe it is possible to make this feature available for this package as well.

I might try that on the weekend and report to this issue. ;)

[saitho]

I got it working. :) Added a PR: #8

[DoctorMcKay]

Thanks for implementing this!

[saitho]

This wasn't merged yet, was it? There is still the open PR. #8

[Revadike]

This wasn't merged yet, was it? There is still the open PR. #8

@DoctorMcKay