Create tutorial on upgrading from v1 to v2

[cholmes]

We are starting to get users who use v1 and aren't sure how they'd go about upgrading to v2. See #630.

Let's work to get some good documentation out soon that walks people through changes from v1 to v2. Probably would be good to have one for both the python API and the CLI.

[cholmes]

Closing this in favor of #784