Remove py27 completely from tox

tox.ini

@@ -9,17 +9,17 @@ commands = pylint -rn --rcfile={toxinidir}/pylintrc {toxinidir}/astroid
 # pylint: git+https://github.com/pycqa/pylint@master
 [testenv]
 deps =
-  py27,pypy: backports.functools_lru_cache
-  py27,pypy: enum34
+  pypy: backports.functools_lru_cache
+  pypy: enum34
   lazy-object-proxy
   ; we have a brain for nose
   ; we use pytest for tests
   nose
-  py27,py34,py35,py36: numpy
-  py27,py34,py35,py36: attr
+  py34,py35,py36: numpy
+  py34,py35,py36: attr
   pytest
   python-dateutil
-  py27,pypy: singledispatch
+  pypy: singledispatch
   six
   wrapt
   pylint: pylint