SLEEVE: Add funds check for sleeve travel (#1298)

This makes it consistent with player behaviour. This also makes the function description more truthful in that it is now possible to return false.

src/PersonObjects/Sleeve/Sleeve.ts

@@ -256,6 +256,10 @@ export class Sleeve extends Person implements SleevePerson {
 
   /** Travel to another City. Costs money from player */
   travel(newCity: CityName): boolean {
+    if (!Player.canAfford(CONSTANTS.TravelCost)) {
+      return false;
+    }
+
     Player.loseMoney(CONSTANTS.TravelCost, "sleeves");
     this.city = newCity;
 

src/ScriptEditor/NetscriptDefinitions.d.ts

@@ -4473,7 +4473,7 @@ export interface Sleeve {
   setToGymWorkout(sleeveNumber: number, gymName: string, stat: string): boolean;
 
   /**
-   * Make a sleeve travel to another city.
+   * Make a sleeve travel to another city. The cost for using this function is the same as for a player.
    * @remarks
    * RAM cost: 4 GB
    *