Fix test

vrp-core/src/lib.rs

@@ -92,7 +92,7 @@
 //! // run solver and get the best known solution.
 //! let solution = Solver::new(problem, config).solve()?;
 //!
-//! assert_eq!(solution.cost, 42.);
+//! assert_eq!(solution.cost, 84.);
 //! assert_eq!(solution.routes.len(), 1);
 //! assert_eq!(solution.unassigned.len(), 0);
 //! # Ok::<(), GenericError>(())