User can add a guest to their trip via typing in their email

[StephanieCherubin]

• Add guests page should say "Name, Email, Add guest button"

• Method 1: Instead of an email sent to the guest, after the user clicks the add guest button, it will tell the user to give them a secret code. The guest will then add the code upon logging in.

• Method 2:: The guest gets an email to be added to the trip. The email contains a link where the trip details will be after they sign up.They will have access to the dashboard and albums and chatroom.