Call evaluate_pre() instead of evaluate() on Maybe decider

e19142c introduced evaluate_pre to
perform context unrolling before to call the semi-public evaluate().

The Maybe decider was not updated at that time, but its context need to
be unrolled.

factory/declarations.py

@@ -490,7 +490,7 @@ def evaluate_post(self, instance, step, overrides):
             return target
 
     def evaluate_pre(self, instance, step, overrides):
-        choice = self.decider.evaluate(instance=instance, step=step, extra={})
+        choice = self.decider.evaluate_pre(instance=instance, step=step, overrides={})
         target = self.yes if choice else self.no
 
         if isinstance(target, BaseDeclaration):

factory/faker.py

@@ -43,7 +43,7 @@ def __init__(self, provider, **kwargs):
             **kwargs)
 
     def evaluate(self, instance, step, extra):
-        locale = extra.pop('locale', None)
+        locale = extra.pop('locale')
         subfaker = self._get_faker(locale)
         return subfaker.format(self.provider, **extra)