Customer discount with prefill discount in sales.

bookie/src/app/core/customer-discount.ts

@@ -0,0 +1,12 @@
+export class CustomerDiscount {
+  id: string;
+  name: string;
+  discount: number;
+
+  public constructor(init?: Partial<CustomerDiscount>) {
+    this.id = '';
+    this.name = '';
+    this.discount = 0;
+    Object.assign(this, init);
+  }
+}