Fix for force_str vs force_text under python 2

tastypie/compat.py

@@ -47,8 +47,10 @@ def unsalt_token(token):
         return token
 
 
-# compatability for force_text (deprecated) vs force_str (new)
-try:
-    from django.utils.encoding import force_str  # noqa
-except ImportError:
+# force_text deprecated in 2.2, removed in 3.0
+# note that in 1.1.x, force_str and force_text both exist, but force_str behaves
+# much differently on python 3 than python 2.
+if django.VERSION < (2, 2):
     from django.utils.encoding import force_text as force_str  # noqa
+else:
+    from django.utils.encoding import force_str  # noqa