fix json encoding by encoding bytes as ascii

pyaccuwage/__init__.py

@@ -101,6 +101,9 @@ def json_dumps(records):
             if hasattr(o, 'toJSON') and isinstance(getattr(o, 'toJSON'), collections.Callable):
                 return o.toJSON()
 
+            if type(o) is bytes:
+                return o.decode('ascii')
+
             elif isinstance(o, decimal.Decimal):
                 return str(o.quantize(decimal.Decimal('0.01')))