clan-config: init

- nixos-modules to jsonschema converter
- nix unit testing via adisbladis/nix-unit
- clan config: configuration CLI for nixos-modules

pkgs/clan-cli/tests/config/test.nix

@@ -0,0 +1,8 @@
+# run these tests via `nix-unit ./test.nix`
+{ lib ? (import <nixpkgs> { }).lib
+, slib ? import ../../clan_cli/config/schema-lib.nix { inherit lib; }
+}:
+{
+  parseOption = import ./test_parseOption.nix { inherit lib slib; };
+  parseOptions = import ./test_parseOptions.nix { inherit lib slib; };
+}