Travel
The travel represents a single travel. This means the travel is not bound to a single spot. (Of course, it is possible.)
When you go on the honeymoon, you can go to Europe, then Asia, America, and so on. In this case, the travel will be 'Honeymoon' instead of 'Europe', 'Asia'...
Attributes
Travel ID
This is UUID
Name
Arbitrary string. More than 0, and less than and equal to 100.
Start Date
Date with timezone
End Date
Data with timezone. This can be null. You can start a journey following your heart, and stop your journey when you find the place you want to live.
Travelers
The user ID collection. This represents actual travelers.
Involved Users
The user ID collection. This represents involved people like host.