Adding reference to money-uphold-bank

[naps62]

https://github.com/subvisual/money-uphold-bank

I build this bank integration to work with the API from https://uphold.com/

It's mainly because I'm building a couple of products for this API, but it has the interesting aspect of supporting Litecoin, Bitcoin, Ethereum and any other currency that might eventually get added to Uphold itself

(these crypto currencies are only visible by the Money gem if you register them manually)

[coveralls]

Coverage remained the same at 99.382% when pulling 4e96ceb on naps62:mp-uphold into 35b71b9 on RubyMoney:master.

[antstorm]

Looking good! Might be worth adding network error handling to your gem, but it works.

[naps62]

@antstorm yes, I'll consider that, thanks. This is just what I came up with in about an hour, since I needed this ASAP