replace make serve with nominatim serve command

With the website directory now tied to the project directory instead
of the build directory, it is no longer possible to use make for
running the web server.

test/python/test_cli.py

@@ -215,6 +215,14 @@ def test_replication_update_continuous_no_change(monkeypatch, temp_db_conn, stat
     assert sleep_mock.last_args[0] == 60
 
 
+def test_serve_command(monkeypatch):
+    func = MockParamCapture()
+    monkeypatch.setattr(nominatim.cli, 'run_php_server', func)
+
+    call_nominatim('serve')
+
+    assert func.called == 1
+
 @pytest.mark.parametrize("params", [
                          ('search', '--query', 'new'),
                          ('reverse', '--lat', '0', '--lon', '0'),