Adding --no-color flag to stylelint args (#5050)

* Adding --no-color flag to sass stylelint

* Adding --no-color to all stylelint args

* Adding --no-color expectation to stylelint tests

* Properly handling SyntaxError for stylelint; adding corresponding test

* Fixing CSS stylelint parameters and adding regression test

ale_linters/sass/stylelint.vim

@@ -9,6 +9,6 @@ call ale#linter#Define('sass', {
 \   'executable': {b -> ale#path#FindExecutable(b, 'sass_stylelint', [
 \       'node_modules/.bin/stylelint',
 \   ])},
-\   'command': '%e --stdin-filename %s',
+\   'command': '%e --no-color --stdin-filename %s',
 \   'callback': 'ale#handlers#css#HandleStyleLintFormat',
 \})