Test

Make `validate_not_null_constraint`, `remove_foreign_key` and `remove… #536

Job	Run time
lint	10s
test (2.7, activerecord_61.gemfile)	1m 4s
test (2.7, activerecord_70.gemfile)	1m 9s
test (2.7, activerecord_71.gemfile)	57s
test (3.3, activerecord_80.gemfile)	46s
test (3.3, activerecord_head.gemfile)	47s
	4m 53s

Provide feedback