returns the balance in wei
        with some inspiration from PyWallet

def get_balance(self, address, api_token):
        """
        returns the balance in wei
        with some inspiration from PyWallet
        """
        broadcast_url = self.base_url + '?module=account&action=balance'
        broadcast_url += '&address=%s' % address
        broadcast_url += '&tag=latest'
        if api_token:
            '&apikey=%s' % api_token
        response = requests.get(broadcast_url)
        if int(response.status_code) == 200:
            balance = int(response.json().get('result', None))
            logging.info('Balance check succeeded: %s', response.json())
            return balance
        raise BroadcastError(response.text)