add last_seen serializer

billard/serializers.py

@@ -1,9 +1,15 @@
 from rest_framework import serializers
 
-from billard.models import LocationData
+from billard.models import LocationData, Client
 
 
 class LocationDataSerializer(serializers.HyperlinkedModelSerializer):
     class Meta:
         model = LocationData
         fields = ('client_id', 'desk_no', 'tst', 'on_off',)
+
+
+class ClientUpdateLastSeenSerializer(serializers.HyperlinkedModelSerializer):
+    class Meta:
+        model = Client
+        fields = ('uuid', 'last_seen')