Add linting env to tox.

Author: Lukasa

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py34, py35, pypy
+envlist = py27, py34, py35, pypy, lint
 
 [testenv]
 deps= -r{toxinidir}/test_requirements.txt
@@ -11,3 +11,8 @@ commands=
 [testenv:pypy]
 # temporarily disable coverage testing on PyPy due to performance problems
 commands= py.test {toxinidir}/test/
+
+[testenv:lint]
+basepython=python3.5
+deps = flake8==2.5.4
+commands = flake8 --max-complexity 10 hyper test