NavigationExperimental Bug

When using NavigationExperimental.CardStack with enableGestures={false}, the first transition always ends by rendering the last card, regardless of the target.

Expected:

1. Render a CardStack with two cards, 0 and 1, starting on 1
2. Trigger a transition to card 0
3. Card 0 is animated into frame
4. After animation, card 0 is shown

Actual:

1. Render a CardStack with two cards, 0 and 1, starting on 1
2. Trigger a transition to card 0
3. Card 0 is animated into frame
4. After animation, card 1 is shown

Code to reproduce:

The code to reproduce the issue can be found in Example/index.js, but the main culprit seems to be the enableGestures props in the code below:

<NavigationExperimental.CardStack
  enableGestures={false}
  navigationState={this.state}
  renderScene={this.renderScene}
/>

This might be due to a bug in the native animation, which is only available if enableGestures is false.