Add an --update flag to inittestdb to add tests to existing database (#4088)
Add an --update flag to inittestdb to add tests to existing database (#4088)

I usually want to create a database with just the testing databases I
use most often, and its frustrating to have to redo the bootstrap when
I need another.
edgedb/edgedb,edgedb/edgedb,edgedb/edgedb