Support "~/" path

[azu]

{
    "rules": {
        "prh": {
            "rulePaths" :["~/path/to/prh.yml"]
        }
    }
}

feedback from http://note103.hateblo.jp/entry/2016/06/13/074744

[azu]

Does we use https://www.npmjs.com/package/untildify ?