Proper jsonb field encoding

Signed-off-by: Lee Smet <lee.smet@hotmail.com>

heromodels/examples/postgres_model_example.rs

@@ -179,6 +179,12 @@ fn main() {
         print_user_details(inactive_user);
     }
 
+    // Delete a user based on an index for good measure
+    db.collection::<User>()
+        .expect("can open user collection")
+        .delete::<username, _>("janesmith")
+        .expect("can delete existing user");
+
     println!("\n--- User Model Information ---");
     println!("User DB Prefix: {}", User::db_prefix());