test-check-code: prevent files being added to the root directory Adding new files in the root directory is probably a mistake, and is usually discouraged [1]. The test catches it to avoid mistakes like [2]. Modify the test if files need to be added in the root. [1]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-July/086442.html [2]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095836.html