Clean up the production db after #2673

In #2673 we removed a lot of redundant DDL from schema.sql. However, this took us out of sync with production. The branch.sql file here syncs up production with the new output of schema.sql (apart from permission settings).

```
$ psql gittip-bak < branch.sql
$ pg_dump -sO gittip-bak > old.sql
$ make schema
$ pg_dump -sO gittip > new.sql
$ diff old.sql new.sql 
981,990d980
< -- Name: public; Type: ACL; Schema: -; Owner: -
< --
< 
< REVOKE ALL ON SCHEMA public FROM PUBLIC;
< REVOKE ALL ON SCHEMA public FROM postgres;
< GRANT ALL ON SCHEMA public TO postgres;
< GRANT ALL ON SCHEMA public TO PUBLIC;
< 
< 
< --
$
```