Update __init__.py
Update __init__.py

Put "United States" at the head of the list, which will make it a default for credit cards.
studio666/gratipay.com,eXcomm/gratipay.com,eXcomm/gratipay.com,eXcomm/gratipay.com,mccolgst/www.gittip.com,gratipay/gratipay.com,eXcomm/gratipay.com,gratipay/gratipay.com,studio666/gratipay.com,mccolgst/www.gittip.com,studio666/gratipay.com,mccolgst/www.gittip.com,studio666/gratipay.com,gratipay/gratipay.com,gratipay/gratipay.com,mccolgst/www.gittip.com