Added support for django-nonrel string AutoField primary key.

Author: DAV3HIT3

simple_history/models.py

@@ -265,7 +265,11 @@ def get_field(self, other, cls):
         if isinstance(to_field, models.OneToOneField):
             field = self.get_one_to_one_field(to_field, other)
         elif isinstance(to_field, models.AutoField):
-            field.__class__ = models.IntegerField
+			# Check if AutoField is string for django-non-rel support
+			if isinstance(field, models.TextField):
+				field.__class__ = models.TextField
+			else:
+				field.__class__ = models.IntegerField
         else:
             field.__class__ = to_field.__class__
             excluded_prefixes = ("_", "__")
@@ -319,7 +323,12 @@ def transform_field(field):
     if isinstance(field, models.AutoField):
         # The historical model gets its own AutoField, so any
         # existing one must be replaced with an IntegerField.
-        field.__class__ = models.IntegerField
+		if isinstance(field, models.TextField):
+			# Check if AutoField is string for django-non-rel support
+			field.__class__ = models.TextField
+		else:
+			field.__class__ = models.IntegerField
+
     elif isinstance(field, models.FileField):
         # Don't copy file, just path.
         field.__class__ = models.TextField