Fix config only being found below the working dir

[zed0]

The glob used to find files to lint was also being used to walk up to
find configuration files. Given a file layout like:

foo/
    .htmlhintrc
    bar/
        test.html

htmlhint would not pick up the configuration if foo/bar/ was the working
directory, however it would if foo/ was the working directory.

[coveralls]

Coverage remained the same at 98.734% when pulling c1d4e8a on zed0:master into 152a114 on yaniswang:master.