Blank/null IATA code isn't unique when added #679 (#681)

app/Contracts/FormRequest.php

@@ -2,6 +2,8 @@
 
 namespace App\Contracts;
 
+use Illuminate\Validation\Rule;
+
 class FormRequest extends \Illuminate\Foundation\Http\FormRequest
 {
     /**
@@ -21,4 +23,18 @@ class FormRequest extends \Illuminate\Foundation\Http\FormRequest
     {
         return [];
     }
+
+    /**
+     * Set a given column as being unique
+     *
+     * @param $table
+     *
+     * @return array
+     */
+    public function unique($table)
+    {
+        return [
+            Rule::unique($table)->ignore($this->id, 'id'),
+        ];
+    }
 }