Merge pull request #3380 from metabase/remove-unused-tables-and-columns

resources/migrations/042_remove_unused_tables.yaml

src/metabase/db/migrations.clj

src/metabase/middleware.clj

src/metabase/models/user.clj

src/metabase/query_processor.clj

test/metabase/api/card_test.clj

test/metabase/api/dashboard_test.clj

test/metabase/api/database_test.clj

test/metabase/api/field_test.clj

test/metabase/api/table_test.clj

test/metabase/api/user_test.clj

test/metabase/events/revision_test.clj

test/metabase/test/util.clj