Add test for multiple resolving service bounded as singleton

src/Gin/Foundation/Theme.php

@@ -90,7 +90,6 @@ public function get($key, array $parameters = [])
         // Otherwise, look for service
         // in services collection.
         if (isset($this->services[$key])) {
-
             // Resolve service jf we don't have
             // a deposit for this service.
             if (! isset($this->deposit[$key])) {

tests/Gin/Foundation/ThemeTest.php

@@ -117,6 +117,23 @@ public function it_should_return_same_object_on_factory_binding()
         $this->assertNotSame($theme->get('factory'), $theme->get('factory'));
     }
 
+    /**
+     * @test
+     */
+    public function it_should_create_service_only_once_on_multiple_resolving()
+    {
+        $theme = Theme::getInstance();
+        $mock = Mockery::mock(new Stub);
+
+        $theme->bind('service', function () use ($mock) { return $mock->action(); });
+
+        $mock->shouldReceive('action')->once()->andReturn('value');
+
+        $theme->get('service');
+        $theme->get('service');
+        $theme->get('service');
+    }
+
     /**
      * @test
      */
@@ -128,4 +145,12 @@ public function it_should_throw_exception_on_resolving_nonexisting_binding()
 
         $theme->get('nonexsiting.binding');
     }
+}
+
+class Stub
+{
+    function action()
+    {
+        //
+    }
 }