Fixed #6 "zoomed in" issue

ios/lib/ReactNativeCameraKit/CKCamera.m

@@ -175,6 +175,9 @@ RCT_ENUM_CONVERTER(CKCameraZoomMode, (@{
         // Create the AVCaptureSession.
         self.session = [[AVCaptureSession alloc] init];
 
+        // Fit camera preview inside of viewport
+        self.session.sessionPreset = AVCaptureSessionPresetPhoto;
+        
         // Communicate with the session and other session objects on this queue.
         self.sessionQueue = dispatch_queue_create( "session queue", DISPATCH_QUEUE_SERIAL );