added withdraw_bitcoins functionality and fixed the spec so everything passes
added deposit address and unconfirmed user deposits, also fixed unnessesary requests in the withdraw method
Merge pull request #12 from jb-san/withdraw_bitcoins

added withdraw_bitcoins
Merge pull request #13 from jb-san/deposit_bitcoins

Deposit bitcoins
Merge branch 'master' of github.com:kojnapp/bitstamp into jruby-compatibility

Conflicts:
	spec/fixtures/vcr_cassettes/bitstamp/order_book.yml