Merge remote-tracking branch 'origin/master' into drawer

# Conflicts:
#	App.js
#	src/Scene/HomeScene.js
#	src/Scene/UpgradeScene.js
#	src/Scene/VideoScene.js
#	src/components/MainDrawerNavigator.js

src/Scene/HomePage.js

@@ -82,7 +82,7 @@ export default class HomePage extends Component {
             </View>
             <Text style={[styles.instructions, { color: 'red' }]}>current: {this.state.selectedItem}</Text>
           </View>
-          <HoverButton navigation={this.props.navigation} />
+          <HoverButton navigation={this.props.navigation}/>
         </SideMenu>
       );
     }

src/Scene/VideoScene.js

@@ -3,6 +3,8 @@ import { StyleSheet, StatusBar } from 'react-native';
 import { Container } from 'native-base';
 import VideoPlayer from 'react-native-video-controls';
 import Orientation from 'react-native-orientation';
+import PropTypes from 'prop-types';
+import { StackActions } from 'react-navigation';
 
 const styles = StyleSheet.create({
   backgroundVideo: {
@@ -36,14 +38,29 @@ export default class VideoScene extends Component {
       <Container>
         <StatusBar hidden />
         <VideoPlayer
+          ref={(ref) => {
+            this.video = ref;
+          }}
           source={{
             uri: VideoScene.getVideoURL()
           }}
-          // disableBack
+          controls
           onEnterFullscreen={() => Orientation.lockToLandscape()}
           onExitFullscreen={() => Orientation.lockToPortrait()}
+          onBack={() =>
+            this.props.navigation.dispatch(
+              StackActions.pop({
+                n: 1
+              })
+            )
+          }
+          progressUpdateInterval={250.0}
         />
       </Container>
     );
   }
 }
+
+VideoScene.propTypes = {
+  navigation: PropTypes.object.isRequired
+};