Move apps in main directory

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

logs/apps.py

@@ -0,0 +1,18 @@
+# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.apps import AppConfig
+from django.db.models.signals import post_delete, post_save, pre_save
+from django.utils.translation import gettext_lazy as _
+
+
+class LogsConfig(AppConfig):
+    name = 'logs'
+    verbose_name = _('Logs')
+
+    def ready(self):
+        # noinspection PyUnresolvedReferences
+        from . import signals
+        pre_save.connect(signals.pre_save_object)
+        post_save.connect(signals.save_object)
+        post_delete.connect(signals.delete_object)