Fix tox compatibility

closes gh-88

Author: bigbes

tarantool/const.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # pylint: disable=C0301,W0105,W0401,W0614
 
-import six
+import sys
 
 #
 IPROTO_CODE = 0x00
@@ -87,7 +87,7 @@
 # Default delay between attempts to reconnect (seconds)
 RECONNECT_DELAY = 0.1
 
-if six.PY2:
+if sys.version_info.major == 2:
     ENCODING_DEFAULT = None
 else:
     ENCODING_DEFAULT = "utf-8"

tarantool/request.py

@@ -5,6 +5,7 @@
 '''
 
 import six
+import sys
 import msgpack
 import hashlib
 
@@ -123,7 +124,7 @@ def sha1(values):
             return sha.digest()
 
         def strxor(rhs, lhs):
-            if six.PY2:
+            if sys.version_info.major == 2:
                 return "".join(chr(ord(x) ^ ord(y)) for x, y in zip(rhs, lhs))
 
             return bytes([x ^ y for x, y in zip(rhs, lhs)])