Edit:
    CHANGES.txt
    nptdms/version.py

Commit and tag with version, push to GitHub.
Eg:
    git commit -m "Version 0.5.0"
    git tag 0.5.0
    git push --tags origin master

Upload a new package to pypi:
    python setup.py sdist upload

Pypi credentials are stored in ~/.pypirc
Username is adamreeve, password is Qa..X..
