these are allowed to be null

apps/addons/models.py

@@ -102,7 +102,7 @@ class Addon(amo.models.ModelBase):
     the_reason = TranslatedField()
     the_future = TranslatedField()
 
-    average_rating = models.CharField(max_length=255, default=0,
+    average_rating = models.CharField(max_length=255, default=0, null=True,
                                       db_column='averagerating')
     bayesian_rating = models.FloatField(default=0, db_index=True,
                                         db_column='bayesianrating')

apps/users/models.py

@@ -45,7 +45,7 @@ class UserProfile(amo.models.ModelBase):
     password = models.CharField(max_length=255, default='')
     email = models.EmailField(unique=True)
 
-    averagerating = models.CharField(max_length=255, blank=True)
+    averagerating = models.CharField(max_length=255, blank=True, null=True)
     bio = PurifiedField()
     confirmationcode = models.CharField(max_length=255, default='',
                                         blank=True)
@@ -55,7 +55,7 @@ class UserProfile(amo.models.ModelBase):
     emailhidden = models.BooleanField(default=False)
     homepage = models.CharField(max_length=255, blank=True, default='')
     location = models.CharField(max_length=255, blank=True, default='')
-    notes = models.TextField(blank=True)
+    notes = models.TextField(blank=True, null=True)
     notifycompat = models.BooleanField(default=True)
     notifyevents = models.BooleanField(default=True)
     occupation = models.CharField(max_length=255, default='', blank=True)