* make fonts larger (md-body instead of md-caption)
* use only color and sizes from variables.scss
* use less different colors
* simplify CSS rules

Please check out this change and compare to previous version.

Now variables are in variables.css in frontend directory. Previously they were in assets, which was wrong because it caused copy to production image.

This change adds linter for styles to the project and updates all styles
to conform with the default set of rules.

This should help us maintain a little bit more consistency in our
styles.

Added check to prevent display of replica set list page when there are no replica sets.