Add CSV support for studio_people script.

[ashercodeorg]

My intention is to run the script on staging, test, and levelbuilder in the no argument mode and on production in the argument mode.

It has already been run on test before these changes. Though slow, it isn't unreasonably slow and saves me from needing to generate the CSV.

Unfortunately, I'm not sure how best to get this run in all developer environments. Given the lack of index on User.user_type, I'm not sure how to generate an appropriate migration.

MANUAL TESTING: Created a CSV, eliminated existing StudioPersons (avoiding the before_save callback on User), and ran the script with the CSV.

[ashercodeorg]

Note that if there was a convenient way to touch a record without changing it, this could alternately be done by user.touch && user.save!. Unfortunately, newer versions of Rails seem not to support touch as expected.

[ashercodeorg]

Note that this will update the updated_at timestamp. This seems desirable, though if desired, I can disable that.

[Hamms]

Could you just create a standard rails migration, but gate it to run only on the development environment? It won't be performant, but dev dbs are usually small enough that that shouldn't be a huge issue

[Hamms]

worth adding a safeguard for teachers who converted to students in between CSV generation and script run?

[ashercodeorg]

Yes. Doing so.

[ashercodeorg]

A development only migration might be necessary. There was discussion at some point on Slack that we didn't want to have environment specific migrations, though.