title: How do I force a component to unmount when I navigate to a new page in react native?
body: <p>I want to make sure the lifecycle method ComponentWillUnmount fires when I navigate to a new page.  I found this <a href="https://stackoverflow.com/questions/30241083/how-to-remove-or-unmount-a-component-in-react-native">post</a>, but that doesn't seem to mention anything about navigating to a new page.  I also found this <a href="https://stackoverflow.com/questions/37647087/react-native-when-componentwillunmount-will-be-called">post</a> but I'm using react-navigation.  In addition, I'm not using pop/push.  I'm simply using this.props.navigation.navigate('SomePage') to get to the next page</p>