Merge branch '144-url-lesson-does-not-exist-an-thus-can-t-be-resolved' into 'master'

Resolve "URL "lesson" does not exist and thus can't be resolved"

Closes #144

See merge request !150

aleksis/apps/alsijil/menus.py

@@ -14,7 +14,7 @@ MENUS = {
             "submenu": [
                 {
                     "name": _("Current lesson"),
-                    "url": "lesson",
+                    "url": "lesson_period",
                     "icon": "alarm",
                     "validators": [
                         (