Cutting a DistArray release

Steps to cutting a DistArray release:

1. Check all of the open issues and PRs assigned to the current release milestone on GitHub. For each one, either close it or reassign it to another milestone.
2. Make sure all the examples still work and the tests pass.
3. Update features.ipynb to reflect any added features in this release.
4. Update the API docs: distarray/docs/source/distarray.rst and friends.
5. Add a release notes document: distarray/docs/source/releases/release-<version>.rst.
6. Update any other related docs (in docs, README.rst etc.).
7. Update the website (at least add the new release-notes).
8. Update MANIFEST.in (if necessary; check the output of python setup.py sdist).
9. Bump version numbers in the code and docs to the release version (probably just remove -dev).
10. Tag the release and push it to GitHub.
11. Edit the release notes on GitHub (just use the release notes document).
12. Add a version of the docs on distarray.readthedocs.org for the tagged version.
13. Push the release to PyPI (check out the tagged version and push from it).
14. Announce the release (on relevant mailing lists and elsewhere).
15. Close the release milestone on GitHub.
16. Bump version numbers in code and docs to <next-version>-dev.

Note: We follow Semantic Versioning (http://semver.org/)