Update tests
Tests: Better error message in mocha reporter
Sass: New ast format
SCSS: New ast format
Bin: Make `gonzales.js` executable
Bin: Add bin to generate `.json` test files
Tests: Simplify `test.coffee` files
Tests: Generate missing `.json` test files for CSS
Tests: Clean up `test.coffee` files

Add missing tests and remove nonexisting ones.
Tests: Fix sass tests, convert to correct syntax
Tests: Remove unused sass tests
Tests: Unskip green tests
Less: Fix `delim` node
Sass: Fix `commentML` node