fix incorrect locations schema in error

Author: joonlabs

src/Errors/GraphQLError.php

@@ -38,7 +38,7 @@ public function __construct(string $message = "", array $node = null, array $pat
      */
     public function getLocations(): ?array
     {
-        return $this->node["loc"] ?? null;
+        return [$this->node["loc"]] ?? null;
     }
 
     /**

tests/Errors/ErrorTest.php

@@ -19,7 +19,7 @@ public function testConvertNodeToPosition()
             ]
         ];
         $Error = new GraphQLError("message", $node);
-        self::assertSame($Error->getLocations(), $node["loc"]);
+        self::assertSame($Error->getLocations(), [$node["loc"]]);
     }