Merge pull request #13 from chexex/fix_issue_8_TypeError

Fix "TypeError: coercing to Unicode: need string or buffer...

djangoseo/backends.py

@@ -448,7 +448,7 @@ class ModelMetadataBase(MetadataBaseModel):
             objects = self.get_manager(options)()
 
             def __str__(self):
-                return self._content_type
+                return str(self._content_type)
 
             def _process_context(self, context):
                 """ Use the given model instance as context for rendering