Fix#6: Define TAG in .gitlab-ci.yml and update scripts to defer to it.
renamed: scripts/push-test-image.sh -> scripts/push-image.sh
renamed: scripts/test-tag.sh -> scripts/test-image.sh
Refactored some of the scripts/* so they are generic and not tied to CI usages.
Added error checking and output to push-rolling-image.sh and remove-tag.sh
Added scripts/trigger.sh to auto-trigger builds.
Signed-off-by: James Ketrenos <james.p.ketrenos@intel.com>
