Support Python version 3.4 and deprecate 3.3.

Author: tgommers

setup.py

@@ -51,7 +51,7 @@
         "Operating System :: POSIX :: Linux",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.5",
-        "Programming Language :: Python :: 3.3",
+        "Programming Language :: Python :: 3.4",
         "Programming Language :: Python :: 2.7",
         "Topic :: Security"
     ],