mv microsoft/azure-cli to mcr.microsoft.com/azure-cli

[ganezasan]

Checklist

• [y] All new jobs, commands, executors, parameters have descriptions
• [y] Examples have been added for any significant new features
• [y] README has been updated, if necessary

Motivation, issues

Microsoft has changed their namespace of the Docker Hub, and it causes an issue to this orb for pulling a docker image.

Description

• mv microsoft/azure-cli to mcr.microsoft.com/azure-cli

[just-evgenyevlampev]

@ganezasan, @lokst could you please fix this problem here https://github.com/CircleCI-Public/azure-aks-orb/issues/11?