Checking for time has a different format expectation

[MaicolBen]

Since we upgraded to 3.1.0, this match have_enqueued_sidekiq_job(id).in(20.minutes) fails randomly only in the CI:

       expected to have an enqueued MyWorker job 
         arguments: [1] 
         options: {"in"=>20 minutes}
 
       found 
         arguments: [[1]] 
         options: [{"at"=>1593448009.99905}]

That seems weird since in that code we don't have at