Add PostgreSQL 9.6 to the test matrix

Author: The-Alchemist

.travis.yml

@@ -6,6 +6,7 @@ env:
   - PGVERSION=9.3
   - PGVERSION=9.4
   - PGVERSION=9.5
+  - PGVERSION=9.6
 before_script:
   - export PATH=/usr/lib/postgresql/$PGVERSION/bin:$PATH     # Add our chosen PG version to the path
   - sudo /etc/init.d/postgresql stop                         # Stop whichever version of PG that travis started