Many of the tests in validations_test would add a new validation to
models. However, only Topic was being reset with a fairly aggressive
clearing of all validations. None of the other models being used however
were recieving the same treatment. Now we use repair_validations(Topic)
for the whole test case because most test cases use Topic and then the
block form of repair_validations(<other_models>) inside any tests that use
other models.
Signed-off-by: Pratik Naik <pratiknaik@gmail.com>