Add gitter chat badge.
Fix singleton variable warning in test.
Strip prolog header from test output.
Fix the bootstrap instructions.

It had broken due to GitHub serving a 301 which we weren't following.
Merge pull request #13 from myfreeweb/master

brew-cask support, bash -> sh, etc.
Update on any cask package install.
Abstract out symlinking predicates.
add idempotent deps