add testing framework

tests/minimal.nix

@@ -0,0 +1,32 @@
+#  nixos-mailserver: a simple mail server
+#  Copyright (C) 2016-2017  Robin Raymond
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program. If not, see <http://www.gnu.org/licenses/>
+
+import ./../../nixpkgs/nixos/tests/make-test.nix {
+
+  # Either the configuration of a single machine:
+  machine =
+    { config, pkgs, ... }:
+    {
+        imports = [
+            ./../mail-config.nix
+        ];
+    };
+
+  testScript =
+    ''
+      $machine->waitForUnit("multi-user.target");
+    '';
+}