Cannot activate ios8 custom keyboard on actual device

I have designed a custom keyboard for iOS8 and it's working perfectly fine on the simulator but when I connect my iPad to Xcode to have the app on my device, it doesn't show my custom keyboard under the keyboards list. What am I doing wrong? The implementation of my keyboard could be found here.

After step by step committing code, I found something interesting. In my application I have some web files like index.html, CSS folder JS folder. My application works fine just before copying these files inside of the project. Once I add them and run the program, it won't show my custom keyboard under the keyboards list. I think it's a bug, please correct me if I'm wrong.

Edited I tried to add folders one by one and test the app after changes. I added JS, CSS folders successfully. I have a folder called plugins. As soon as I add this folder to the project as a reference folder, my custom keyboard will disappear. If I remove this folder, delete the app from device and run it again, my custom keyboard will come back. This is definitely a bug for iOS8.