Remove py33 from docs (#92)

Author: laymonage

README.rst

@@ -702,7 +702,7 @@ OR |Documentation Status|
 Requirements
 ------------
 
--  Python >= 2.7 or >= 3.3
+-  Python >= 2.7 or >= 3.4
 
 For SDK developers
 ------------------
@@ -719,7 +719,6 @@ Run tests
 Test by using tox. We test against the following versions.
 
 -  2.7
--  3.3
 -  3.4
 -  3.5
 -  3.6