Returns all groups
successful operation
The name of the group
The type of the group - e.g. band
The number of members in the group
The number of customers assigned to the group
The number of regular bookings the group has
The number of bookings the group has
Unix timestamp from epoch - when the group was created
Unix timestamp from epoch - when the group was last updated
Unix timestamp from epoch - when the group last booked
The customers assigned to the group
The group's regular bookings