tests: move to t, allow yath test from root

By moving the tests subdirectory to t, we gain the ability to run `yath
test` with no arguments from inside `nix develop` in the root of the
the repo.

(`nix develop` is necessary in order to set the proper env vars for
`yath` to find our test libraries.)

t/build-products.t

@@ -0,0 +1,42 @@
+use strict;
+use Setup;
+
+my %ctx = test_init();
+
+require Hydra::Schema;
+require Hydra::Model::DB;
+
+use Test2::V0;
+
+my $db = Hydra::Model::DB->new;
+hydra_setup($db);
+
+
+# Test build products
+
+my $jobset = createBaseJobset("build-products", "build-products.nix", $ctx{jobsdir});
+
+ok(evalSucceeds($jobset),               "Evaluating jobs/build-products.nix should exit with return code 0");
+is(nrQueuedBuildsForJobset($jobset), 2, "Evaluating jobs/build-products.nix should result in 2 builds");
+
+for my $build (queuedBuildsForJobset($jobset)) {
+    subtest "For the build job '" . $build->job . "'" => sub {
+        ok(runBuild($build), "Build should exit with code 0");
+        my $newbuild = $db->resultset('Builds')->find($build->id);
+
+        is($newbuild->finished, 1, "Build should have finished");
+        is($newbuild->buildstatus, 0, "Build should have buildstatus 0");
+
+        my $buildproducts = $db->resultset('BuildProducts')->search({ build => $build->id });
+        my $buildproduct = $buildproducts->next;
+
+        if($build->job eq "simple") {
+            is($buildproduct->name, "text.txt", "We should have \"text.txt\"");
+        } elsif ($build->job eq "with_spaces") {
+            is($buildproduct->name, "some text.txt", "We should have: \"some text.txt\"");
+        }
+    };
+
+}
+
+done_testing;