`Test::Unit` is deprecated, and we can switch to `Minitest::Test` with
almost no side effects.
This commit does all of the work required to make Minitest tests run
with Gollum's existing test helpers.
* CSS to SCSS
* Use sprockets
* Use Sprockets helpers
* Fix gollum.editor.js error when changing language
* Add keybinding files required by ace and some ace ext files that are required or might be useful.
* Move app paths to /gollum namespace, add route helpers for view templates
* Use path helper for links in page view
* Use path helper methods in javascript assets
* Refactored sprockets helpers for mustache
* Remove debugging
benjamin wil
Dawa Ometto
Bart Kamphorst
Roman Bambycha