Added tab view (not working)

Aurora/Design/Converters/NullToBullConverter.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Globalization;
+using Xamarin.Forms;
+
+namespace Aurora.Design.Converters
+{
+    public class NullToBoolConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return value != null;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return null;
+        }
+    }
+}