title: Undefined is not an object (evaluating 'this.props.navigator.replace')
body: <p>I followed a tutorial to use React-Navigation, I got a problem when trying to move to another page. I get this error:<code>Undefined is not an object (evaluating 'this.props.navigator.replace')</code></p>
  
  <p>I searched here and on other sites but nothing worked for me.
  This is the code I have:</p>
  
  <p>index:</p>
  
  <pre><code> import React, { Component } from 'react';
   import { Root } from './config/Router';
  
   class Application extends Component{
     render(){
       return &lt;Root /&gt;;
     }
   }
  
  export default Application;
  </code></pre>
  
  <p>Router:</p>
  
  <pre><code>import React from 'react';
  import { StackNavigator } from 'react-navigation';
  
  import Login from '../pages/Login';
  import Home from '../pages/Home';
  
  export const Root = StackNavigator({
    Login:{
      screen: Login,
    },
    Home:{
      screen: Home,
      navigatorOptions:{
        title: "Homepage"
      }
    }
  });
  </code></pre>
  
  <p>Login (when clicking the button here, the problem occurs):</p>
  
  <pre><code>  export default class Login extends Component{
    constructor(props){
      super(props);
    }
    _navigate(routeName){
      this.props.navigator.replace({
        name: routeName
      });
    }
    render(){
      return(
         &lt;View style = {styles.container}&gt;
            &lt;TouchableOpacity onPress={this._navigate.bind(this, 'Home')}&gt;
              &lt;Text&gt;
                Hello.
              &lt;/Text&gt;
            &lt;/TouchableOpacity&gt;
         &lt;/View&gt;
      );
    }
  }
  </code></pre>
  
  <p>What am I doing wrong ?</p>
  
  <p>Thanks in advance.</p>