Use `mocha` option instead of globals

https://github.com/jshint/jshint/blob/c3a72b81eba2f6fc76660e1b025ead6bf5
071073/src/vars.js#L656-L669
Update bower.json to follow the spec

https://github.com/bower/bower.json-spec#version

Authors don’t have to set `version` field explicitly.
Add `files` field to package.json

https://www.npmjs.org/doc/files/package.json.html#files