Adding a groups to recipients function in Helper.
Adding confirm page to scheduling reminders.
Adding function to aggregate recipients into groups.
Merge pull request #240 from codeforamerica/rebeccav1.4

Rebeccav1.4
added count of recipients for sent reminders
fixed public home page
added reminder destroy method. this will delete queued rreminders in delayed job.
Merge branch 'develop' of https://github.com/codeforamerica/promptly into develop