Update setup.py with python 3 info

Author: samuell

setup.py

@@ -40,8 +40,10 @@
         'Natural Language :: English',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2 :: Only',
+        'Programming Language :: Python :: 2',
+        'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3.4',
         'Topic :: Scientific/Engineering',
         'Topic :: Scientific/Engineering :: Bio-Informatics',
         'Topic :: Scientific/Engineering :: Chemistry',