def load_key(self, path):
        """
        Load key and secret from file.
        :param path: path to file with first two lines are key, secret respectively
        """
        with open(path, 'r') as f:
            self.key = f.readline().strip()
            self.secret = f.readline().strip()
Load key and secret from file.
        :param path: path to file with first two lines are key, secret respectively