Directory stx will now be owned by stx-root.
Relocate .gitignore from stx-utils for that directory.
Change-Id: I75ac350600e5dcce286e6a76cf3a985d9297a2a8
Story: 2002801
Task: 22687
Depends-On: https://review.openstack.org/588634
Signed-off-by: Scott Little <scott.little@windriver.com>