Update FreeBSD pg test to use postgresql95-server.

The py-psycopg2 package now requires postgresql95-server instead of
postgresql93-server. Installing py-psycopg2 will automatically remove
postgresql93-server if it is installed, breaking integration tests.

test/integration/targets/setup_postgresql_db/vars/FreeBSD.yml

@@ -1,10 +1,10 @@
 postgresql_packages:
-  - "postgresql93-server"
+  - "postgresql95-server"
   - "py27-psycopg2"
 
 pg_hba_location: "/usr/local/pgsql/data/pg_hba.conf"
 pg_dir: "/usr/local/pgsql/data"
-pg_ver: 9.3
+pg_ver: 9.5
 pg_user: pgsql
 pg_group: pgsql