Performs /register.

        Args:
            auth_body (dict): Authentication Params.
            kind (str): Specify kind of account to register. Can be 'guest' or 'user'.
            bind_email (bool): Whether to use email in registration and authentication.
            username (str): The localpart of a Matrix ID.
            password (str): The desired password of the account.
            device_id (str): ID of the client device.
            initial_device_display_name (str): Display name to be assigned.
            inhibit_login (bool): Whether to login after registration. Defaults to false.

def register(self, auth_body=None, kind="user", bind_email=None,
                 username=None, password=None, device_id=None,
                 initial_device_display_name=None, inhibit_login=None):
        """Performs /register.

        Args:
            auth_body (dict): Authentication Params.
            kind (str): Specify kind of account to register. Can be 'guest' or 'user'.
            bind_email (bool): Whether to use email in registration and authentication.
            username (str): The localpart of a Matrix ID.
            password (str): The desired password of the account.
            device_id (str): ID of the client device.
            initial_device_display_name (str): Display name to be assigned.
            inhibit_login (bool): Whether to login after registration. Defaults to false.
        """
        content = {}
        content["kind"] = kind
        if auth_body:
            content["auth"] = auth_body
        if username:
            content["username"] = username
        if password:
            content["password"] = password
        if device_id:
            content["device_id"] = device_id
        if initial_device_display_name:
            content["initial_device_display_name"] = \
                    initial_device_display_name
        if bind_email:
            content["bind_email"] = bind_email
        if inhibit_login:
            content["inhibit_login"] = inhibit_login
        return self._send(
            "POST",
            "/register",
            content=content,
            query_params={'kind': kind}
        )