Checking the database with methods like Activity.last does not test that
the record is present where it should be (first record of the table in
this case). In these tests there's only one record, though, so the order
doesn't matter that match.
However, calling methods like Activity.last generates a database query
after the process running the browser has been started, and this might
lead to inconsistent data.
Using `have_current_path`, Capybara waits until the condition is true,
while using `include` the expectation is evaluated immediately and so
tests might fail when using a driver supporting JavaScript.
Besides, using `have_current_path` the error message is more readable
when the test fails.
