extrapolation-based PN-kick seems to work better than mikkola's.
adds .travis.yml file.
adds a few sections in README.rst file.
capitalize tupan on travis-ci link in README.rst file.
adds more stuff into .travis.yml file.
adds more stuff into .travis.yml file (II).
integrates tox and travis-ci configuration.
travis-ci apt-get install some packages before run tox.
travis-ci: comment cffi line.
travis-ci: apt-get install some py3 packages.
travis-ci: comment some py3 packages since the CI env can't install them.
travis-ci: build py27 only...
add docs to tox envlist.
tupan script now have a .py extension.