add qualname to conditional priors

Closes #440 (closed)

bilby/core/prior.py

@@ -3492,6 +3492,7 @@ def conditional_prior_factory(prior_class):
             self.condition_func = condition_func
             self._reference_params = reference_params
             self.__class__.__name__ = 'Conditional{}'.format(prior_class.__name__)
+            self.__class__.__qualname__ = 'Conditional{}'.format(prior_class.__qualname__)
 
         def sample(self, size=None, **required_variables):
             """Draw a sample from the prior