Add cask for VisIt, an interactive visualization and graphical analysis
tool used for viewing and analyzing scientific data.
The latest version is 2.7.0, however, downloading and installing it
triggered a virus warning on my computer, and the binary executable
will not run. I am in the process of reporting this issue upstream.
Version 2.6.3 downloads cleanly, installs, and runs on my system,
so the cask downloads that version instead.
Geoffrey Oxberry