refactor to use f-string

tom_observations/facility.py

@@ -39,7 +39,7 @@ def get_service_classes():
         try:
             clazz = import_string(service)
         except (ImportError, AttributeError):
-            raise ImportError('Could not import {}. Did you provide the correct path?'.format(service))
+            raise ImportError(f'Could not import {service}. Did you provide the correct path?')
         service_choices[clazz.name] = clazz
     return service_choices