Send a request for a new cryptocurrency deposit address
        with an optional label. Return the response.

        Arguements:
        currency -- a Gemini supported cryptocurrency (btc, eth)
        label -- optional label for the deposit address

def newAddress(self, currency='btc', label=''):
        """
        Send a request for a new cryptocurrency deposit address
        with an optional label. Return the response.

        Arguements:
        currency -- a Gemini supported cryptocurrency (btc, eth)
        label -- optional label for the deposit address
        """
        request = '/v1/deposit/' + currency + '/newAddress'
        url = self.base_url + request
        params = {
            'request': request,
            'nonce': self.get_nonce()
        }

        if label != '':
            params['label'] = label

        return requests.post(url, headers=self.prepare(params))