Remove orchestra testbench.

Author: irazasyed

composer.json

@@ -26,8 +26,7 @@
     },
     "require-dev": {
         "mockery/mockery": "^1.0",
-        "orchestra/testbench": "^3.5 || ^4.0",
-        "phpunit/phpunit": "^6.0 || ^7.0 || ^8.0"
+        "phpunit/phpunit": "^8.0"
     },
     "autoload": {
         "psr-4": {

tests/TelegramChannelTest.php

@@ -3,7 +3,7 @@
 namespace NotificationChannels\Telegram\Test;
 
 use Mockery;
-use Orchestra\Testbench\TestCase;
+use PHPUnit\Framework\TestCase;
 use Illuminate\Notifications\Notifiable;
 use Illuminate\Notifications\Notification;
 use NotificationChannels\Telegram\Telegram;
@@ -29,6 +29,12 @@ public function setUp(): void
         $this->channel = new TelegramChannel($this->telegram);
     }
 
+    public function tearDown(): void
+    {
+        Mockery::close();
+        parent::tearDown();
+    }
+
     /** @test */
     public function it_can_send_a_message(): void
     {