nixos/tests: Enable "partition" as "storage".

Renames the test to closer match the NixOS module attribute and put it
into release.nix. Of course, those tests still fail, because nixpart is
still WIP and I haven't pushed the first version yet.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>

nixos/release.nix

@@ -287,6 +287,7 @@ in rec {
   tests.runInMachine = callTest tests/run-in-machine.nix {};
   tests.sddm = callTest tests/sddm.nix {};
   tests.simple = callTest tests/simple.nix {};
+  tests.storage = callTest tests/storage.nix {};
   tests.tomcat = callTest tests/tomcat.nix {};
   tests.udisks2 = callTest tests/udisks2.nix {};
   tests.virtualbox = hydraJob (import tests/virtualbox.nix { system = "x86_64-linux"; });