Update tox to run pep8 by default.

tools/hacking.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+flake8 barbicanclient | tee flake8.log
+exit ${PIPESTATUS[0]}

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py26, py27
+envlist = py26, py27, pep8
 
 [testenv]
 setenv = VIRTUAL_ENV={envdir}
@@ -18,7 +18,7 @@ deps = -r{toxinidir}/tools/pip-requires
        -r{toxinidir}/tools/test-requires
 
 [testenv:pep8]
-commands = flake8
+commands = {toxinidir}/tools/hacking.sh
 
 [testenv:venv]
 commands = {posargs}