Sort on recursive search

Run clippy

src/testhelpers.rs

@@ -51,8 +51,7 @@ impl UserDao for TestUserDao {
         self.user_map
             .borrow()
             .iter()
-            .find(|&u| u.username == user)
-            .is_some()
+            .any(|u| u.username == user)
     }
 }