Release new version and update PyPI

Hi, there was a significant enhancement which added support for the [psycopg2cffi.sql](https://github.com/chtd/psycopg2cffi/commit/bca6b9c4a21b219845e150eab6cc77ce18d17f5c) module about a year ago. Could you release a new update with this and upload it to PyPI?