Add Tadaya's script to create tag/branch for a release
Add Tadaya's script to create tag/branch for a release

The release-tag.sh scripts just creates a tag and a branch given a
commit after doing some validation.
Deploying to nexus is handled by a jenkins job.

Change-Id: I7247059104da6d264e27134b00dd11be3698f12d

toliaqat/xenon,toliaqat/xenon,toliaqat/xenon,toliaqat/xenon,toliaqat/xenon