ci: fix python 3.5 by adding to tox.ini

Also, switch back from the python-coveralls package to the
primary coveralls package as it appears to be better maintained
now.

Signed-off-by: Paul Osborne <osbpau@gmail.com>

Author: posborne

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py32,py33,py34,pypy,pypy3
+envlist = py27,py32,py33,py34,py35,pypy,pypy3
 
 [testenv]
 passenv = TRAVIS TRAVIS_JOB_ID TRAVIS_BRANCH
@@ -10,7 +10,7 @@ commands=nosetests --with-doctest --doctest-options='+ELLIPSIS,+NORMALIZE_WHITES
 [testenv:coverage]
 deps=
   {[testenv]deps}
-  python-coveralls
+  coveralls
 commands =
   coverage run --branch --omit={envdir}/* {envbindir}/nosetests
   coveralls