Creating a new release

Follow PEP 440.

1. Create a new branch x.y.z.
2. Change the version number in neurodocker/version.py
3. Update the examples in README.md
4. Tag x.y.z branch as x.y.z (use git tag -a)
5. Build wheel (python setup.py bdist_wheel)
6. Test installation of wheel in fresh python3 docker container
7. Upload wheel file to PyPi with twine upload dist/*
8. Build new Docker container and upload to DockerHub

Adapted from scikit-learn's wiki.