Merge branch 'esap-general#55' into 'master'

Warn when fetching basket fails

See merge request astron-sdc/esap-userprofile-python-client!5

shopping_client/shopping_client.py

@@ -76,7 +76,7 @@ class shopping_client:
                     "shopping_cart"
                 ]
             else:
-                return None
+                warn(f"Unable to load data from {self.host}; is your key valid?")
 
         if filter_archives:
             self.basket = self._filter_on_archive()