V2 top bar text font family (#1634)

* screen Background Color iOS

* ios v2 topBarTextFontFamily

lib/ios/RNNNavigationOptions.h

 @property (nonatomic, strong) NSString* title;
 @property (nonatomic, strong) NSNumber* screenBackgroundColor;
 @property (nonatomic, strong) NSString* setTabBadge;
+@property (nonatomic, strong) NSString* topBarTextFontFamily;
 
 -(instancetype)init;
 -(instancetype)initWithDict:(NSDictionary *)navigationOptions;

lib/ios/RNNNavigationOptions.m

 	self.topBarBackgroundColor = [navigationOptions objectForKey:@"topBarBackgroundColor"];
 	self.statusBarHidden = [navigationOptions objectForKey:@"statusBarHidden"];
 	self.title = [navigationOptions objectForKey:@"title"];
-	self.topBarTextColor = [navigationOptions objectForKey:@"topBarTextColor"];
 	self.screenBackgroundColor = [navigationOptions objectForKey:@"screenBackgroundColor"];
 	self.setTabBadge = [navigationOptions objectForKey:@"setTabBadge"];
+	self.topBarTextFontFamily = [navigationOptions objectForKey:@"topBarTextFontFamily"];
 	return self;
 }
 
 	}
 	if (self.topBarTextColor) {
 		UIColor* textColor = [RCTConvert UIColor:self.topBarTextColor];
-		viewController.navigationController.navigationBar.titleTextAttributes = @{NSForegroundColorAttributeName:textColor};
+		NSMutableDictionary* navigationBarTitleTextAttributes = [NSMutableDictionary dictionaryWithDictionary:@{NSForegroundColorAttributeName: textColor}];
+		if (self.topBarTextFontFamily) {
+			[navigationBarTitleTextAttributes addEntriesFromDictionary:@{NSFontAttributeName: [UIFont fontWithName:self.topBarTextFontFamily size:20]}];
+		}
+		viewController.navigationController.navigationBar.titleTextAttributes = navigationBarTitleTextAttributes;
+	} else if (self.topBarTextFontFamily){
+		viewController.navigationController.navigationBar.titleTextAttributes = @{NSFontAttributeName: [UIFont fontWithName:self.topBarTextFontFamily size:20]};
 	}
 	if (self.screenBackgroundColor) {
 		UIColor* screenColor = [RCTConvert UIColor:self.screenBackgroundColor];
 
 
 
-
 @end

playground/src/containers/OptionsScreen.js

 class OptionsScreen extends Component {
   static navigationOptions = {
     title: 'Static Title',
-    topBarBackgroundColor: "red"
+    topBarBackgroundColor: "red",
+    topBarTextFontFamily: "HelveticaNeue-Italic"
   }
 
   constructor(props) {
     Navigation.setOptions(this.props.containerId, {
       title: 'Dynamic Title',
       topBarTextColor: '#00FFFF',
-      topBarBackgroundColor: 'green'
+      topBarBackgroundColor: 'green',
+      topBarTextFontFamily: "HelveticaNeue-CondensedBold"
     });
   }
 }