Make ret event symbols more clear with arrow and bold

src/Job.vue

@@ -108,7 +108,7 @@ export default class Job extends Vue {
       else if (Object.keys(ret.changes).length !== 0) return 'Δ';
       else return '✓';
     } else if (this.isJobEventType(event, 'ret')) {
-      return event.data.success ? '✓' : '✗';
+      return event.data.success ? '→✔' : '→✘';
     }
     return '?';
   }