A createApp function for Vue 2.7

[scottbedard]

Hi all 👋

I spent the last year migrating a truly massive codebase to 3.x. Easily the most important strategy our team found was to keep diff off the migration branch. One of the keys to doing this was building a createApp function that worked like 3.x.

Now that we're done, I've cleaned it up and extracted it to a stand-alone repo. Good luck to anyone still migrating, I hope this helps!

https://github.com/scottbedard/vue-forward