Fix setting item visibility timeout (#131) I am unsure why it happened now. Was it introduced in DispatchRider 2.0 or 2.1 ? Was it a change upstream in aws-sdk-sqs ? * test using `ensure`, because item.visibility_timeout krash * use change visibility * make aws sns/sqs required runtime gem * fix openstruct in specs * use a proc * require gems, do not rescue NameError exceptions * bump version * stub object for the method call instead * rubocop