A whitelist files allows the user to specify a list of regexes
that ostestr will expand and run. It is mutually exclusive with
blacklist, but not mutually exclusive with --regex/path.
The value of --regex/path is appended to the whitelist.
Co-Authored-By: Davanum Srinivas <davanum@gmail.com>
Change-Id: Ic397212ef3127c176a5870676f67d8a5e0de0441
368a2553cd