Updated relationships to be nullable

ref #11 #13

src/models/GroupContact.ts

@@ -55,7 +55,7 @@ export class GroupContact {
    * Optional
    */
   @IsOptional()
-  @ManyToOne(() => Address, address => address.participants)
+  @ManyToOne(() => Address, address => address.participants, { nullable: true })
   address?: Address;
 
   /**
@@ -79,12 +79,12 @@ export class GroupContact {
   /**
    * Used to link the contact as the donor of a donation.
    */
-  @OneToMany(() => Donation, donation => donation.donor)
+  @OneToMany(() => Donation, donation => donation.donor, { nullable: true })
   donations: Donation[];
 
   /**
     * Used to link runners to donations.
     */
-  @OneToMany(() => RunnerGroup, group => group.contact)
+  @OneToMany(() => RunnerGroup, group => group.contact, { nullable: true })
   groups: RunnerGroup[];
 }