remove post-nominals and add isManager property

mongodb/Staff.ts

@@ -13,9 +13,6 @@ export default class Staff {
   @prop()
   public dept: string;
 
-  @prop()
-  public pn: string[];
-
   @prop()
   public emailAddress: string;
 
@@ -27,4 +24,7 @@ export default class Staff {
 
   @prop()
   public additionalRoles: string[];
+
+  @prop({ default: false })
+  public isManager: boolean;
 }