Add gpg_auth to Linux.

ansible/roles/ssh_client/files/gpg_auth_linux

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+#
+# Wrapper to set the SSH auth socket to GPG for services that do not
+# yet support security key ssh keys
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+exec env SSH_AUTH_SOCK="${XDG_RUNTIME_DIR}/gnupg/S.gpg-agent.ssh" "$@"