Update to new registry domain

[jgarcows]

Getting started labs should be updated to work with the new registry domain names.

https://www.ibm.com/blogs/bluemix/2019/02/introducing-new-ibm-cloud-container-registry-domain-names/

There are some worries about backwards compatibility, so those will have to be considered, but it is definitely the way going forward.

[bhpratt]

completed