#218 - Change backend to allow users to request feedback from multiple users
#218 - Fix 'request feedback' form UI to describe multiple email input
added test to check for existing invitations
fixed issues with flash in invitations_contoller showing up improperly
Use invitation validation error messages in controller
refactored validations for invitations and removed @example.com emails
updated UserMailer to send notifications to coaches when new feedback is submitted
Merge pull request #66 from bsmith3541/multipleEmail

refactored validation for invitations
Merge remote-tracking branch 'upstream/master'