A work in progress. You can watch us livecode it on http://emacsrocks.com All keybindings in buster-mode start with `C-c C-b` and then a two-letter mnemonic shortcut. * `td`: toggle-deferred will toggle // in the name of the current test. * `tf`: toggle-focus-rocket will toggle => in the name of the current test. * `ra`: run-all-tests