use postgres 9.4 for tests

setup_test_db.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 if [ -z $(which initdb) ] ; then
-    echo "Postgres not found, you may need to launch like so: PATH=\$PATH:/usr/lib/postgresql/9.3/bin/ $0"
+    echo "Postgres not found, you may need to launch like so: PATH=\$PATH:/usr/lib/postgresql/9.4/bin/ $0"
     exit 1
 fi