Service: Add Bedford service types, part2

[kevinrobinson]

Migration step 2 for #2535, split out to isolate test changes.

Next is #2536.

[kevinrobinson]

hmm, can't make sense of this: https://travis-ci.org/studentinsights/studentinsights/jobs/565628102#L3137

It seems the migration is silently failing, and just isn't doing what it says it's doing ❓ 😕

[kevinrobinson]

k, .column_names is cached, and the cache is on that model's class so explicitly clearing that with ServiceType.reset_column_information now.

[kevinrobinson]

huh today I learned table structure is cached across migration files, never would have expected that and don't understand how migrations ever work at all then but not going to dig further now :) References:

• https://stackoverflow.com/a/11355761/5711971
• https://api.rubyonrails.org/classes/ActiveRecord/Migration.html
• reset_column_information not called after each migration rails/rails#6939 (comment)
• this scenario described: https://github.com/rails/rails/pull/7050/files

And splitting it into separately PRs or commits doesn't resolve the issue either, since all migrations run at once in a clean Travis environment anyway. Still not sure why this didn't reproduce locally though; I thought I had dropped and re-run all migrations. Either way, shipping this and moving on.

[kevinrobinson]

selfie