* invalid drive letter breaks new Powershell path validation (this is a separate issue that needs to be solved)
* test also exposes a minor bug in win_get_url where a nonexistent directory in the root of a drive that exists passes the "does the parent dir exist" check and causes DownloadFile to bomb (this should be fixed by dag's rewrite of win_get_url in https://github.com/ansible/ansible/pull/26612)
This change corrects problems reported by the `yamllint` linter.
Since key duplication problems were removed in 4d48711, this commit
mainly fixes trailing spaces and extra empty lines at beginning/end of
files.
