feat: add workaround method for Config::get_array()
feat: add workaround method for Config::get_array()

Version `0.4.1` of `config-rs` has a bug where the
`Config::get_array()` method consumes `self` instead of taking `self`
by reference like its other methods. The Rust compiler then complains
that the config variable has been moved and disallows any future use
of it. The bug has been fixed by the authors of `config-rs`, but at
this time the fix has not been released on crates.io. Until then, our
new function, `ref_get_array()`, will serve that purpose.

Afulton11/contrail