WIP -- adding upload reminders for parents:

* move test/unit/lib to test/lib
* add database cleaner functionality to tests
* start to add actual upload reminder functionality
* schedule upload reminders
move unit tests around to make sure they're all running
finish adding sms notifier
WIP sending parents reminders to upload photo of kid(s):

* add ability to manage reminders from the admin
* add default value in DB for reminder preference
* add user email index (not unique)
WIP testing reminder functionality manually using real services:

* add some basic environment config
* make email more configurable
* fix sms method call bug (remove `.deliver`)
WIP leveraging reminders via rake task:

* update scheduler to point at correct rake task
* properly handle case where `parent_ids` is empty set in `ParentReminders`
Merge pull request #7 from kcbigring/reminders

Add upload reminders for parents