message: Removed spring from twitter motion
diff: import React from 'react';
  import {Dimensions, View} from 'react-native';
  -import {NavigationMotion, spring} from 'navigation-react-native';
  -
  -const getStyle = (translate, scale, opacity) => ({
  - translate: spring(translate),
  - scale: spring(scale),
  - opacity: spring(opacity)
  -});
  +import {NavigationMotion} from 'navigation-react-native';
  export default ({stateNavigator, startStateKey, visible}) => (
  <NavigationMotion
  startStateKey={startStateKey}
  - unmountedStyle={getStyle(1, 1, 1)}
  - mountedStyle={getStyle(0, 1, 1)}
  - crumbStyle={getStyle(0.05, 0.9, 0)}
  + unmountedStyle={{translate: 1, scale: 1, opacity: 1}}
  + mountedStyle={{translate: 0, scale: 1, opacity: 1}}
  + crumbStyle={{translate: 0.05, scale: 0.9, opacity: 0}}
  style={{flex: +visible, backgroundColor: 'black'}}
  stateNavigator={stateNavigator}>
  {({translate, scale, opacity}, scene, url) => (
  