Bump psycopg2 from 2.7.3.2 to 2.7.4 in /backend/uclapi
Bump psycopg2 from 2.7.3.2 to 2.7.4 in /backend/uclapi

Bumps [psycopg2](http://initd.org/psycopg/) from 2.7.3.2 to 2.7.4.
uclapi/uclapi,uclapi/uclapi,uclapi/uclapi,uclapi/uclapi