pypy3 support

[NP-Hardass]

Hello,
I didn't see pypy3 listed in the supported implementations, nor does it appear to be included in your travis.yml test suite. Seems to be working on my end as is, for 0.11. Passed tests on a Gentoo amd64 system.

[warner]

Thanks for checking that.. I've added it to the .travis.yml, so it should be included in future test runs.