title: react-navigation go Back not navigate to previous screen
body: <p>I'm using new react-navigation 2.16.0 in my react-native app.</p>
  
  <p>I have welcome (login and register) screen and then Main stack. main stack include all screens after success auth(login\register).</p>
  
  <pre><code>MainStack = createStackNavigator(
              {
                  Welcome: {
                      screen: Welcome, navigationOptions: {
                          gesturesEnabled: false,
                      }
                  },
                  Main: {
                      screen: App, navigationOptions: {
                          gesturesEnabled: false,
                      }
                  }
  
  
  
              }, {
                  headerMode: 'none',
                  lazy: true,
                  initialRouteName: UserStore.token ? 'Main' : 'Welcome',
                  gesturesEnabled: false,
                  cardStack: {
                      gesturesEnabled: false
                  },
                  cardStyle: {
                      elevation: 0,
                      shadowOpacity: 0,
                      borderBottomWidth: 0,
                      borderTopWidth: 0
  
                  },
                  transitionConfig: () =&gt; ({
                      containerStyle: {
                          elevation: 0,
                          shadowOpacity: 0,
                          borderBottomWidth: 0,
                          borderTopWidth: 0
                      }
                  }),
              }
          )`
  </code></pre>
  
  <p>Main stack render</p>
  
  <pre><code>render() {
  
  
      // const splashDone = this.state.splashDone &amp;&amp; this.state.backSplash
      const ready = UserStore.storeHydrated
  
      console.log('Current Routes', NavigationStore)
      // console.log('AppStore.loading ', AppStore.loading)
      return (
          &lt;View style={{ flex: 1,backgroundColor:'transparent'}}&gt;
          &lt;StatusBar
              barStyle="light-content"
          /&gt;
              {!splashDone ? &lt;SplashScreen /&gt; : null}
  
              {ready &amp;&amp;
                  &lt;Provider {...stores}&gt;
  
                      &lt;MainStack 
  
                      /&gt;
  
                  &lt;/Provider&gt;}
  
              &lt;InternetConnectionPopUp /&gt;
  
              {AppStore.loading ?
                  &lt;Spinner
                      color={colors.yellow}
                      style={{ position: 'absolute', right: 0, left: 0, top: 0, bottom: 0, zIndex: 99999 }} /&gt;
                  : null}
  
              &lt;View style={Platform.OS === 'ios' &amp;&amp; this.state.flag ? { height: calcSize(25) } : {}} /&gt;
          &lt;/View&gt;
      )
  }
  </code></pre>
  
  <p>App.js</p>
  
  <pre><code>    import React, { Component } from 'react'
  import { BackHandler, Alert, AppState, View,Keyboard } from 'react-native'
  import { inject, observer } from 'mobx-react/native'
  import { AppStack } from '../../routes'
  import { NavigationActions } from 'react-navigation'
  import { Header } from '../../components';
  let popupOpen = false
  
  @inject('AppStore') @observer
  class App extends Component {
      constructor(props) {
          super(props)
          this.state = {
              appState: AppState.currentState,
              nowMounted: false
  
          }
          this.goBack = this.goBack.bind(this)
  
      }
  
      goBack() {
          this.props.navigation.goBack(null)
      }
  
      componentWillMount() {
          this.setState({ nowMounted: true })
      }
  
  
  
  
  
  
      render() {
          return (
              &lt;View style={{ flex: 1 }}&gt;
                  &lt;Header  onPressBack={this.goBack}/&gt;
                  &lt;AppStack/&gt;
              &lt;/View&gt;
          )
      }
  }
  
  export default App
  </code></pre>
  
  <p>AppStack.js</p>
  
  <pre><code>import {
      Dashboard,
      Services,
      Schedule,
      ScheduleDays,
      ScheduleTime,
      CancelAppointment
  } from '../screens'
  import { createStackNavigator, NavigationActions } from 'react-navigation'
  
  export const AppStack = createStackNavigator({
  
      Dashboard: { screen: Dashboard, navigationOptions: {
          gesturesEnabled: false,
      } },
  
      Services: { screen: Services, navigationOptions: {
          gesturesEnabled: false,
      } },
      Schedule: { screen: Schedule, navigationOptions: {
          gesturesEnabled: false,
      } },
      ScheduleDays: { screen: ScheduleDays, navigationOptions: {
          gesturesEnabled: false,
      } },
      ScheduleTime: { screen: ScheduleTime, navigationOptions: {
          gesturesEnabled: false,
      } },
      CancelAppointment: { screen: CancelAppointment, navigationOptions: {
          gesturesEnabled: false,
      } },
  }, {
      headerMode: 'none',
      initialRouteName: 'Dashboard',
      lazy: true,
      gesturesEnabled: false,
      cardStack: {
          gesturesEnabled: false
      },
  
  })
  </code></pre>
  
  <p>goBack not works in createStackNavigator, it stay in same screen.
  go Back not works at all.
  when I navigate from dashboard to services screen and then press onBack in services it do nothing.
  I also tried to change instead of createStackNavigator to createSwitchNavigator but still it not works.</p>