Unpin tox for Travis-CI tests because of another bug in tox:
Unpin tox for Travis-CI tests because of another bug in tox:

https://bitbucket.org/hpk42/tox/issues/285/tox-220-breaks-some-toxini-config-files

pecan/pecan,ryanpetrello/pecan,pecan/pecan,jdandrea/pecan,ryanpetrello/pecan,jdandrea/pecan