Create extension hstore
CentOS 7 was released on 2014-07-07.
PostgreSQL 9.3 was released on 2013-09-09. You would think it would have 9.3, but nope. CentOS 7 uses PostgreSQL 9.2 which was released on 2012-09-10 and hits End-Of-Life in September 2017.

Find the official instructions for using the non-CentOS repos here. PostgreSQL maintains it's own packages too. The official packages from PostgreSQL for CentOS are available here,


https://www.postgresql.org/download/linux/redhat/


Or just use something that updates more than once every 5 years -- like Debian.