update setup.py to reflect supported python versions

Author: daler

setup.py

@@ -19,21 +19,19 @@
     description="Work with GFF and GTF files in a flexible "
     "database framework",
     long_description=open("README.rst").read(),
-    author_email='dalerr@niddk.nih.gov',
+    author_email='ryan.dale@nih.gov',
     url='https://github.com/daler/gffutils',
     classifiers=[
         'Intended Audience :: Science/Research',
         'License :: OSI Approved :: MIT License',
         'Topic :: Scientific/Engineering :: Bio-Informatics',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
         'Topic :: Software Development :: Libraries :: Python Modules',
     ],
 )