Fix unicode attribute error if typing installed on py2.7 (#363)

testproj/users/serializers.py

@@ -1,3 +1,5 @@
+import sys
+
 from django.contrib.auth.models import User
 from rest_framework import serializers
 
@@ -6,7 +8,10 @@ from snippets.models import Snippet
 
 try:
     import typing  # noqa: F401
-    from .method_serializers_with_typing import MethodFieldExampleSerializer
+    if sys.version_info >= (3, 4):
+        from .method_serializers_with_typing import MethodFieldExampleSerializer
+    else:
+        from .method_serializers_without_typing import MethodFieldExampleSerializer
 except ImportError:
     from .method_serializers_without_typing import MethodFieldExampleSerializer