Updated README with the description of the second task of the third round
Exposed a method for cron that generates future dates for recurring events
Updated README with description of first task of the third round
Keep future attendees registered when generating new event dates
Admin can edit any event
Updated Rails and other gems
Events can repeat bi-weekly
Event change sends email to attendees informing about these changes
Merge branch 'master' of https://github.com/eballance/ruby-sentiments