added tox.ini
added python 3.4 to travis testing
added PyCharm and tox related files to gitignore
made changes to allow save() calls inside ondelta methods, added tests
updated pyflakes and pep8 to work with python 3.4
bumping version to 0.3.0, adding Python 3.4 to PyPI classifiers
Merge pull request #3 from hwkns/master

Allow self.save() calls from within ondelta_field methods