coinbase/coinbase-ruby — pull request #33 by georgepalmer (2014-04-02 13:17:09+00:00)
Title: Remove Money gem overrides

Money v6 supports BTC so the currency registration should be removed.

Further I don't think you should assume BTC as the default currency. Our site, like many others, offers many currencies and as much as we love BitCoin it isn't the biggest currency we sell in just yet :)