Contribution guidelines

Running tests

Use tox:

pip install tox
tox

Checkout the master branch.
Pull the latest changes from origin.
Make sure check-manifest is happy.
Increment the version number.
Set the correct title for the release in HISTORY.rst.
If needed update the AUTHORS.rst file with new contributors.
Commit everything and make sure the working tree is clean.
Push everything to github and make sure the tests pass on Travis:
```
git push origin master
```
Build and upload the release:
```
./setup.py publish
```

Tag the release:

git tag -a "v$(python setup.py --version)" -m "$(python setup.py --name) release version $(python setup.py --version)"