Prefix css class names

Can you prefix your classes. Some of your css classes have general names (for example: "rating"), and it is causing css conflicts with my app css classes.

Current behavior
CSS class are not prefix.

Expected behavior
Add prefix to CSS classes to avoid conflicts. For example, instead of class-name "rating", it should be renamed to "asr-rating".

**Following classes are effected:**
* .rating
* .star
* .star-container
* .label-value

**Todos:**
- [ ] change classnemes in scss files => use the `#{$var}` syntax
- [ ] change classnames in KSS docs
- [ ] change classnames in Readme.md

Start by locating .rating, .star, .star-container, and .label-value in the SCSS files and review the requested #{$var} syntax. Update the corresponding class names in the KSS docs and Readme.md; done means all listed classes consistently use the asr- prefix.

Written by the indexing model from the issue text.