Path globs support

Hello,
I'd like to ask you to implement support for specifying input files by globs. That would allow us to run htmlcs from build (e.g. npm) scripts in a portable (cross-platform) way. There is actually a lot of linters that accept globs already. They use minimatch AFAIK. I mean some module based on it like globby, glob-all, globule or simple-glob.

[chriswong]

We do this work in fecs：

$ fecs check *.html