Exclude minified JavaScript and CSS

Those files are either external libraries or builds of the repository itself. In any case they are generated automatically and shouldn't count in the language statistics. This also simplifies some of the rules that had to exclude both minified and normal dependencies.
Add tests for minified JavaScript and CSS

Also, exclude -min.css pattern, like already done for JavaScript files
Merge pull request #1654 from danijar/master

Exclude minified JavaScript and CSS