setup: deprecate Python2 support

.travis.yml

@@ -1,8 +1,6 @@
 sudo: false
 language: python
 python:
-  - "2.7"
-  - "3.4"
   - "3.5"
   - "3.6"
 

setup.py

@@ -34,10 +34,7 @@ setup(
         'Intended Audience :: System Administrators',
         'License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)',
         'Operating System :: POSIX',
-        'Programming Language :: Python :: 2.7',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3 :: Only',
         'Topic :: Software Development :: Libraries :: Python Modules',
         'Topic :: System :: Networking',
         'Topic :: Communications',

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py3
+envlist = py3
 [pycodestyle]
 max-line-length = 100
 [pep257]