Add `dentistry` as a therapeutic area.
Merge pull request #61 from alphagov/add-dentistry-to-dsu

Add `dentistry` as a therapeutic area.
Turning these single-selects into multi-selects

Since both of these uses are technically multi-selects, we just have a single select option with is "both of the above" --arg!
Merge pull request #62 from alphagov/remove-single-selects

Turning these single-selects into multi-selects
Add issued date to drug-device-alerts schema

Trello Ticket:
https://trello.com/c/QFE3nYlc/361-add-issued-date-to-medical-safety-alerts-2
Merge pull request #65 from alphagov/feature/add-issued-date

Add issued date to drug-device-alerts schema