Use tornado.testing classes for tests, which use unittest

Rename test directories so the CI is not triggered by changes there

testing.requirements.txt

@@ -2,4 +2,3 @@ pytest
 pytest-asyncio
 pytest-cov
 pytest-mock
-pytest-tornado

tests/server_tests/test_key_handler.py

@@ -0,0 +1,48 @@
+import json
+import pathlib
+
+import pytest
+from tornado.testing import AsyncHTTPTestCase
+
+from srv.server import make_app
+
+
+@pytest.fixture(scope='function')
+def tmp_path_cls(request, tmp_path):
+    request.cls.config_values = tmp_path
+
+
+@pytest.mark.usefixtures("tmp_path_cls")
+class TestKeyHandler(AsyncHTTPTestCase):
+    config_values: pathlib.Path
+
+    def get_app(self):
+        return make_app(self.config_values)
+
+    def test_root(self):
+        response = self.fetch('/')
+        self.assertEqual(response.code, 404)
+
+    def test_not_found(self):
+        response = self.fetch('/key/not-found')
+        self.assertEqual(response.code, 404)
+        # self.assertEqual(response.body, 'Hello, world')
+
+    def test_key(self):
+        test_file = self.config_values / "test"
+        test_file.write_text(json.dumps({"foo": "bar"}))
+
+        response = self.fetch('/key/test')
+        self.assertEqual(response.code, 200)
+        self.assertEqual(response.body.decode(), json.dumps({"foo": "bar"}))
+
+        test_file.unlink()
+
+    def test_key_not_json(self):
+        test_file = self.config_values / "test"
+        test_file.write_text("something: not json")
+
+        response = self.fetch('/key/test')
+        self.assertEqual(response.code, 400)
+
+        test_file.unlink()