Enable SingleLinePerSelector in scss-lint

.scss-lint.yml

app/assets/stylesheets/framework/animations.scss

app/assets/stylesheets/framework/blocks.scss

app/assets/stylesheets/framework/buttons.scss

app/assets/stylesheets/framework/common.scss

app/assets/stylesheets/framework/dropdowns.scss

app/assets/stylesheets/framework/flash.scss

app/assets/stylesheets/framework/gitlab-theme.scss

app/assets/stylesheets/framework/header.scss

app/assets/stylesheets/framework/lists.scss

app/assets/stylesheets/framework/mobile.scss

app/assets/stylesheets/framework/nav.scss

app/assets/stylesheets/framework/selects.scss

app/assets/stylesheets/framework/tables.scss

app/assets/stylesheets/framework/tw_bootstrap.scss

app/assets/stylesheets/framework/typography.scss

app/assets/stylesheets/highlight/dark.scss

app/assets/stylesheets/highlight/monokai.scss

app/assets/stylesheets/highlight/solarized_dark.scss

app/assets/stylesheets/highlight/solarized_light.scss