Tastes like a "recipe" for disaster.
Why automate it? How are you going to trust the results? What data points will define success at each stage?
Jumping from 6.0 to 6.3 will involve a repository migration before you upgrade.
Lastly, AEM 6.3 will be end-of-core-support in April 2020, 5-6 months from now. If you're going through the effort to migrate off AEM 6.0 why not jump to 6.5 and set yourself up for long-term success.
I think automating the upgrade is a waste of time and is something that should be manually performed.
But that's just me. Good luck