Use correct version of pg_dump to avoid restore errors

[jfinzel]

We do this in the following way in our DBA environment, though we are all running on Debian, so it's considerably easier:

1. Get the version from cluster_info. This could also be done with SHOW server_version; Our specific script that gives us this is clusterinfo-vars payments_a --version. Refer to https://git.enova.com/cfengine/postgres/blob/master/DBA-Tools/clusterinfo-vars for this script.

2. Find the path of the binary using the version, i.e.

#!/bin/bash

set -eu

destination_cluster=$1
eval "$(clusterinfo-vars $destination_cluster version)"
echo "/usr/lib/postgresql/$version/bin"