React native app with navigation

App.js

import React from 'react';
import {StackNavigator} from "react-navigation";
import {AppRegistry, Button} from "react-native";

class MainScreen extends React.Component {
  static navigationOptions = {
    title: 'Main'
  };

  render() {
    const {navigate} = this.props.navigation;
    console.log(this.props);
    return (
      <Button
        title="Profil"
        onPress={() => navigate('Profile')}
      />
    );
  }
}

class ProfileScreen extends React.Component {
  static navigationOptions = {
    title: 'Profil'
  };

  render() {
    const {goBack} = this.props.navigation;
    return (
      <Button
        title="Go back"
        onPress={() => goBack()}
      />
    );
  }
}

export default StackNavigator({
  Main: {screen: MainScreen},
  Profile: {screen: ProfileScreen},
});