Fix pylint errors

marietje/queues/models.py

@@ -150,7 +150,7 @@ class Queue(models.Model):
             song_count += 1
 
     def __str__(self):
-        return self.name
+        return str(self.name)
 
 
 class QueueCommand(models.Model):
@@ -162,4 +162,4 @@ class QueueCommand(models.Model):
     command = models.TextField()
 
     def __str__(self):
-        return self.command
+        return str(self.command)

pylintrc

@@ -150,6 +150,7 @@ disable=missing-docstring,
         missing-format-attribute,
         too-few-public-methods,
         unused-argument,
+        signature-differs,
 
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option