Add minimum firmware version

[cdthompson]

We could leverage wist to find or enforce minimum firmware versions, something which is required for Roku app submission. The Roku SDK docs are pretty good at documenting which version recent features were introduced. They could be put into a rule or set of rules in order to verify.

[nishtahir]

This is a great idea. We'd need a way to index the APIs though 🤔. It would be very useful if there was a way to do this besides scraping the confluence pages.