Resize custom UIInputViewController in iOS 9 using nib

Question

In my App I'm using a custom keyboard. Not the kind of app extension that requires users to install the keyboard and then be able to use it anywhere - Just in my app.

To do this, I have created a subclass of UIInputViewController and set my keyboard in a custom nib file. Then, on the textfields I require this keyboard to be shown, it calls the inputView of the UIInputViewController.

This is the code calling the Keyboard:

let myKeyBoard = MyKeyboard()    
scoreField.inputView = myKeyBoard.inputView!
scoreField.becomeFirstResponder()

Then, in the UIInputViewController, this code is called:

class MyKeyboard: UIInputViewController {
var myKeyBoardView: UIInputView!

override func viewDidLoad() {
    super.viewDidLoad()

    self.loadInterface()
}

func loadInterface() {
    //load nib and set in view
    let nib = UINib(nibName: "MyKeyboard", bundle: nil)
    myKeyBoardView = nib.instantiateWithOwner(self, options: nil)[0] as! UIInputView
    self.inputView = myKeyBoardView
    view.backgroundColor = myKeyBoardView.backgroundColor
}

This gives you an idea what my code looks like so far. What I want to do now is to set the height of this keyboard to a custom value, say 200. I have scanned google and SO and all solutions I find are either iOS 8 only, or indicate not to be working with a nib file. I think it would be useful to have some knowledge on how to go about this in iOS 9 and WITH a nib too.

How do I change the height of my custom UIInputViewController in iOS 9 with a nib?