Fixed donor address check

ref #105

src/models/entities/Address.ts

@@ -59,8 +59,9 @@ export class Address {
   /**
    * Checks if this is a valid address
    */
-  public get isValidAddress(): Boolean {
-    if (!this.address1 || !this.city || !this.country || !this.postalcode) { return false; }
+  public static isValidAddress(address: Address): Boolean {
+    if (address == null) { return false; }
+    if (address.address1 == null || address.city == null || address.country == null || address.postalcode == null) { return false; }
     return true;
   }
 }