Allow decorators in the parent app.
Prevent view errors if no menu/courses present.
Order Courses within a Menu
Add a flag to determine if a guest is a child.
Rewrite default scope to be RDBMS-agnostic.
Add a method to invitations to check if any kids are invited.

Intended to be used in the view layer to conditionally display info
for parents if any children are invited.
Permit notes field when RSVPing.
Add .all to guests in guest_list

If an invitation was loaded by a .join on the 'guests' table
(which happens when searching for an inviation by guest name),
and all the guests didn’t match the join conditions,
then all guests are not present on the in-memory invitation, meaning
they weren’t output on the guest_list.
Update Readme.