remove all bill related stuff

db/booking.ts

@@ -8,18 +8,16 @@ import {
 } from '../helpers/date'
 import { createCalendarEvent, deleteCalendarEvent } from '../lib/googlecalendar'
 
-import { IBill } from './bill'
 import { BOOKING_STATUS, VALIDATION_ERRORS } from './enums'
 
 export interface IBooking {
   uuid: string
   name: string
   email: string
-  phone: string
+  phone?: string
   street: string
   zip: string
   city: string
-  bill?: IBill
   // format YYYY-MM-DD
   startDate: string
   // format YYYY-MM-DD
@@ -29,10 +27,7 @@ export interface IBooking {
   org?: string
   destination?: string
   days?: string[]
-  calendarEventId: string
-
-  createdAt?: string
-  updatedAt?: string
+  calendarEventId?: string
   toJSON?: () => IBooking
 }
 
@@ -54,11 +49,6 @@ const BookingSchema = new mongoose.Schema(
     street: { type: String, required: true },
     zip: { type: String, required: true },
     city: { type: String, required: true },
-    bill: {
-      type: mongoose.Schema.Types.ObjectId,
-      ref: 'Bill',
-      required: false,
-    },
     startDate: {
       type: String,
       required: true,