message: Ensured valid style values
  Without this react motion keeps restyling, calling children function
  forever
diff: @@ -3,10 +3,10 @@ import {StyleSheet, View} from 'react-native';
  import {NavigationMotion, spring} from 'navigation-react-native';
  const getStyle = ({x, y, w, h}, show) => ({
  - x: spring(x, {stiffness: 250}),
  - y: spring(y, {stiffness: 250}),
  - w: spring(w, {stiffness: 250}),
  - h: spring(h, {stiffness: 250}),
  + x: spring(x || 0, {stiffness: 250}),
  + y: spring(y || 0, {stiffness: 250}),
  + w: spring(w || 0, {stiffness: 250}),
  + h: spring(h || 0, {stiffness: 250}),
  show: spring(show, {stiffness: 250}),
  });
  @@ -15,7 +15,7 @@ export default ({stateNavigator}) => (
  startStateKey="grid"
  unmountedStyle={(state, data) => ({...getStyle(data, 0)})}
  mountedStyle={(state, data) => ({...getStyle(data, 1)})}
  - crumbStyle={{show: spring(1)}}
  + crumbStyle={{...getStyle({}, 1)}}
  style={{flex: 1}}
  stateNavigator={stateNavigator}>
  {({show, x, y, w, h}, scene, state, {color}) => (
  