This rule was added in rubocop-rspec 2.19.0.
When freezing time in a test, `travel_back` is called automatically when
the test finishes, so we can do it in a `before` block instead of an
`around` block.
Note this rule didn't detect our usage of `freeze_time` because we were
using it on cops with a certain tag, but I expect the rule to be able to
detect this usage in the future.
fc0511f4d3