Edit user submit form header text -

Copy is now more specific that submitting form will
setup the user to receive concert notifications
Add phone validation on user form submit

Alert user if phone is not 10 digits and prevent
form submit. Server will add +1 before submission.
Add user model phone validation

Presence if not guest user
10 digits
must be unique
Add users controller phone validation

twilio sms request will not send unless all
user validation passes

Add error event to ajax post. Temporarily alert to errors - will
change in next refactor to render errors in view
Add parsed phone to users controller

Twilio is now passed the user's phone number that has been
appended with +1.
Edit user registration placeholder text

Phone form now informs users that the phone number entered
must only contain numbers - this will be validated on both
client and server sides
Merge pull request #163 from spring-peepers-2014/phone-validation

Add client and server side phone validation.