Don't quote {posargs} in tox.ini
Quotes around {posargs} cause the entire string to be combined into one
arg that gets passed to stestr. This prevents passing multiple args
(e.g. '--concurrency=16 some-regex')
Change-Id: I7e3f0bf2f5999cc0f4b54f68da33debccf077f43
Nguyen Van Trung
5 years ago