* Update docs/submodules/releng from branch 'master'
to 21080b7e95d6a859d090bf0a58620b737a4dd8c4
- Merge "Tagging IPv6 for opnfv-8.0.0"
- Tagging IPv6 for opnfv-8.0.0
Change-Id: I8bb20d09c0553777d55168c8a20084babafb0d7a Signed-off-by: BIN HU <bin.hu@att.com>