Revert "tests: move to _tests"

This reverts commit 4d498aff1a.

tests/eval-test.nix

@@ -0,0 +1,15 @@
+{
+  imports = [ <nixos-hardware-profile> ];
+
+  boot.loader.systemd-boot.enable = true;
+
+  fileSystems."/" = {
+    device = "/dev/disk/by-uuid/00000000-0000-0000-0000-000000000000";
+    fsType = "btrfs";
+  };
+
+  nixpkgs.config = {
+    allowBroken = true;
+    allowUnfree = true;
+  };
+}

tests/eval-test.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+cd $(dirname $0)/..
+
+find=(find . -name default.nix)
+
+for profile in `${find[@]}`; do
+    echo evaluating $profile >&2
+
+    nixos-rebuild \
+	-I nixos-config=tests/eval-test.nix \
+	-I nixos-hardware-profile=$profile \
+	dry-build
+
+    if [ $? -ne 0 ]; then
+	exit 1
+    fi
+done