Re-create https://github.com/rails/rails/pull/21233

eeac6151 was reverted (127509c0) because it breaks tests.

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ref: 72c15572

- We must use `authors` fixture with `author_addresses` because of its foreign key constraint.
- Tests require PostgreSQL >= 9.4.2 because it had a bug about `ALTER CONSTRAINTS` and fixed in 9.4.2.