Implmented cascading donation deletion for runners and donors

ref #66

src/errors/DonorErrors.ts

@@ -33,4 +33,15 @@ export class DonorReceiptAddressNeededError extends NotAcceptableError {
 
 	@IsString()
 	message = "An address is needed to create a receipt for a donor. \n You didn't provide one."
+}
+
+/**
+* Error to throw when a donor still has donations associated.
+*/
+export class DonorHasDonationsError extends NotAcceptableError {
+	@IsString()
+	name = "DonorHasDonationsError"
+
+	@IsString()
+	message = "This donor still has donations associated with it. \n If you want to delete this donor with all it's donations and teams add `?force` to your query."
 }