move CactusCode.org to be hosted by github pages

[Roland Haas]

This current host for https://cactuscode.org has become hard to maintain as well as the website itself very rarely seeing updates. To simplify maintaining it@Ian Hinder and @Steven R. Brandt are exploring hosting it on github’s pages facilities instead.

The current repository is https://github.com/EinsteinToolkit/cactuscode.org in the gh-pages branch and it can be tested at http://test.cactuscode.org/

‌

[Roland Haas]

Once done the reference to the life wavedemo in Cactus’s README.md https://bitbucket.org/cactuscode/cactus/src/master/README.md should be removed.