Add authenticate resource that returns token

This is using a hard-coded admin password!
Require admin for posting send
Switch to in memory key store
Remove requirement for RemindOn date
Return the given RemindOn date
Add rake task with hardcoded values
Cleanup bootstrapper
Add type input to FetchDueReminders
Bump rake send timeout to one minute

Logging message was also added so that reports the total number of
emails to be sent.
Replace hard-coded admin with env var

There is only one authorized user - the admin. The admin's username
and password are stored as an environment variables.
Switch to using current day
Require username and password to have values
Fix rebase conflict
Move urls to config
Prepare for environment based config
Add test that checks for env variables
Add variables for travis auth tests
Reformat travis file
Exclude system tests on travis