Added tests for Image classes

module/Common/test/Image/ImageBuilderFactoryTest.php

@@ -0,0 +1,29 @@
+<?php
+namespace ShlinkioTest\Shlink\Common\Image;
+
+use PHPUnit_Framework_TestCase as TestCase;
+use Shlinkio\Shlink\Common\Image\ImageBuilder;
+use Shlinkio\Shlink\Common\Image\ImageBuilderFactory;
+use Zend\ServiceManager\ServiceManager;
+
+class ImageBuilderFactoryTest extends TestCase
+{
+    /**
+     * @var ImageBuilderFactory
+     */
+    protected $factory;
+
+    public function setUp()
+    {
+        $this->factory = new ImageBuilderFactory();
+    }
+
+    /**
+     * @test
+     */
+    public function serviceIsCreated()
+    {
+        $instance = $this->factory->__invoke(new ServiceManager(), '');
+        $this->assertInstanceOf(ImageBuilder::class, $instance);
+    }
+}