The route configs object is a mapping from route name to a route config, which tells the navigator what to present for that route, see [example](https://github.com/coodoo/react-navigation/blob/master/docs/api/navigators/StackNavigator.md#routeconfigs) from `StackNavigator`.
-`contentComponent` - Component to use to render the navigation items. Receives the `navigation` prop for the drawer. Defaults to `DrawerView.Items`.
-`contentOptions` - Configure the drawer content, see below.
Several options get passed to the underlying router to modify navigation logic:
-`initialRouteName` - The routeName for the initial route.
-`order` - Array of routeNames which defines the order of the drawer items.
-`paths` - Provide a mapping of routeName to path config, which overrides the paths set in the routeConfigs.
-`backBehavior` - Should the back button cause switch to the initial route? If yes, set to `initialRoute`, otherwise `none`. Defaults to `initialRoute` behavior.
### `contentOptions` for `DrawerView.Items`
-`activeTintColor` - label and icon color of the active label
-`activeBackgroundColor` - background color of the active label
-`inactiveTintColor` - label and icon color of the inactive label
-`inactiveBackgroundColor` - background color of the inactive label