Update setup for release supporting python >= 3.5

Author: lsabi

setup.py

@@ -66,9 +66,6 @@
     classifiers=[
         'Intended Audience :: Developers',
         'Natural Language :: English',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
@@ -95,7 +92,7 @@
             'rethinkdb-repl = rethinkdb.__main__:startInterpreter'
         ]
     },
-    python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
+    python_requires=">=3.5",
     install_requires=[
         'six'
     ],