manager: add GcalContext property

This improves access to the GcalContext inside GcalManager.

Also, remove test-manager since it only tests that gcal_manager_new()
returns non-NULL.

tests/meson.build

@@ -35,7 +35,6 @@ tests = [
   'server',
   'discoverer',
   'event',
-  'manager',
 ]
 
 foreach test : tests

tests/test-manager.c

@@ -1,47 +0,0 @@
-/* test-manager.c
- *
- * Copyright (C) 2017 Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <glib.h>
-
-#include "gcal-manager.h"
-
-/*********************************************************************************************************************/
-
-static void
-manager_new (void)
-{
-  g_autoptr (GcalManager) manager;
-
-  manager = gcal_manager_new ();
-
-  g_assert_nonnull (manager);
-}
-
-/*********************************************************************************************************************/
-
-gint
-main (gint   argc,
-      gchar *argv[])
-{
-  g_test_init (&argc, &argv, NULL);
-
-  g_test_add_func ("/manager/new", manager_new);
-
-  return g_test_run ();
-}
-