Regenerate gemspec for version 0.3.1
Regenerate gemspec for version 0.3.1

ondrejbartas/sidekiq-cron,nhoffmann/sidekiq-cron,Eunix/sidekiq-cron,nikolai-b/sidekiq-cron,nhoffmann/sidekiq-cron,Eunix/sidekiq-cron,farainc/sidekiq-cron,ondrejbartas/sidekiq-cron,farainc/sidekiq-cron,nikolai-b/sidekiq-cron