setup.py: Remove 2.4, 2.5 and 2.6 classifiers.

These have not been tested in years, they are likely broken.

Author: vpelletier

setup.py

@@ -48,9 +48,6 @@
         'Intended Audience :: Developers',
         'License :: OSI Approved :: GNU Lesser General Public License v2 or later (LGPLv2+)',
         'Operating System :: OS Independent',
-        'Programming Language :: Python :: 2.4',
-        'Programming Language :: Python :: 2.5',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.4',