LOGGLY-1675, fix hmac raising TypeError

piston/store.py

@@ -13,6 +13,11 @@ def __init__(self, oauth_request):
     def lookup_consumer(self, key):
         try:
             self.consumer = Consumer.objects.get(key=key)
+
+            # LOGGLY-1675, Unicoded Consumers cause hmac.new() to raise TypeError 
+            self.consumer.key = self.consumer.key.encode('ascii')
+            self.consumer.secret = self.consumer.secret.encode('ascii')
+
             return self.consumer
         except Consumer.DoesNotExist:
             return None