Remove empty repo stx-utils

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>

.gitignore

@@ -2,4 +2,3 @@
 /cgcs-centos-repo
 /cgcs-tis-repo
 /cgcs-3rd-party-repo
-/stx

stx/.gitignore

@@ -0,0 +1,20 @@
+.cache/
+*.egg-info
+.idea
+*.pyc
+*.swp
+.tox
+*~
+/downloads
+/git
+installer-prebuilt
+/stx-clients
+/stx-config
+/stx-fault
+/stx-ha
+/stx-integ
+/stx-metal
+/stx-nfv
+/stx-update
+/stx-upstream
+/stx-gui