Return Okay on succesful client creation.

[shachlanAmazon]

Issue #, if available:

Description of changes:

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[barshaul]

@shachlanAmazon
You should fix this function in redis_client.py:

    async def _set_connection_configurations(self) -> None:
        conn_request = self._get_protobuf_conn_request()
        response_future: asyncio.Future = self._get_future(0)
        await self._write_or_buffer_request(conn_request)
        await response_future
        if response_future.result() is not None:
            raise ClosingError(response_future.result())