Start building py3 docker images
Start building py3 docker images

Change-Id: Id6f1075b2774536bb095de0904a1cdcf2b34b0fd

swiftstack/swift,tipabu/swift,tipabu/swift,openstack/swift,openstack/swift,openstack/swift,tipabu/swift,openstack/swift,swiftstack/swift,tipabu/swift,swiftstack/swift