Added a challenge for flying the 3 major airline alliances

app/Models/Alliance.php

@@ -26,6 +26,9 @@ class Alliance extends Model
         'skyteam' => 'airlines_alliances.all_skyteam',
     ];
 
+    const array MAJOR_ALLIANCES = ['skyteam', 'oneworld', 'star_alliance'];
+
+
     public function airlines(): HasMany
     {
         return $this->hasMany(Airline::class);