Refactor project folders.

Move helpdesk to src folder.
Move tests to project base folder.

tests/urls.py

@@ -0,0 +1,8 @@
+from django.contrib import admin
+from django.urls import include, path
+
+
+urlpatterns = [
+    path("", include("helpdesk.urls", namespace="helpdesk")),
+    path("admin/", admin.site.urls),
+]