Improves add_appointment method. Has some pending fixmes

- Start and end time have to be dealt with (changes required on the tower side)
- Sends appointments to every register tower. We may want to manage this better

watchtower-plugin/tower_info.py

@@ -1,19 +1,23 @@
 class TowerInfo:
-    def __init__(self, endpoint, available_slots):
+    def __init__(self, endpoint, available_slots, appointments=None):
         self.endpoint = endpoint
         self.available_slots = available_slots
 
+        if not appointments:
+            self.appointments = {}
+        else:
+            self.appointments = appointments
+
     @classmethod
     def from_dict(cls, tower_data):
         endpoint = tower_data.get("endpoint")
         available_slots = tower_data.get("available_slots")
+        appointments = tower_data.get("appointments")
 
-        if any(v is None for v in [endpoint, available_slots]):
+        if any(v is None for v in [endpoint, available_slots, appointments]):
             raise ValueError("Wrong appointment data, some fields are missing")
-        if available_slots is None:
-            raise ValueError("Wrong tower data, some fields are missing")
 
-        return cls(endpoint, available_slots)
+        return cls(endpoint, available_slots, appointments)
 
     def to_dict(self):
         return self.__dict__