Updating readme with new links.

postgresql/README.md

-# gosexy/db/postgresql
+# PostgreSQL adapter for upper.io/db
 
 Please read the full docs, acknowledgements and examples at
-[http://gosexy.org/db/wrappers/postgresql][1]
+[https://upper.io/db/postgresql][1]
 
-[1]: http://gosexy.org/db/wrappers/postgresql
+[1]: https://upper.io/db/postgresql