fix: add time field to Assignment event (#17)

Author: tyiuhc

src/Amplitude/Event.php

@@ -18,6 +18,7 @@ class Event
     public ?string $userId = null;
     public ?string $deviceId = null;
     public ?string $insertId = null;
+    public ?int $time = null;
 
     public function __construct(string $eventType)
     {
@@ -35,7 +36,8 @@ public function toArray(): array
             'user_properties' => $this->userProperties,
             'user_id' => $this->userId,
             'device_id' => $this->deviceId,
-            'insert_id' => $this->insertId,]);
+            'insert_id' => $this->insertId,
+            'time' => $this->time]);
     }
 
     /**

src/Assignment/Assignment.php

@@ -8,7 +8,7 @@
 use RuntimeException;
 use function AmplitudeExperiment\hashCode;
 
-require_once __DIR__  . '/../Util.php';
+require_once __DIR__ . '/../Util.php';
 require_once __DIR__ . '/AssignmentService.php';
 
 /**
@@ -62,6 +62,7 @@ public function toEvent(): Event
         $event->deviceId = $this->user->deviceId;
         $event->eventProperties = [];
         $event->userProperties = [];
+        $event->time = $this->timestamp;
 
         $set = [];
         $unset = [];