JimEvans: Changing .NET DesiredCapabilities.Safari() to return Desire…

…dCapabilities instead of ICapabilities. Fixes issue SeleniumHQ#4865.

r18248

dotnet/src/WebDriver/Remote/DesiredCapabilities.cs

@@ -279,7 +279,7 @@ public static DesiredCapabilities Opera()
         /// Method to return a new DesiredCapabilities using defaults
         /// </summary>
         /// <returns>New instance of DesiredCapabilities for use with Safari</returns>
-        public static ICapabilities Safari()
+        public static DesiredCapabilities Safari()
         {
             return new DesiredCapabilities("safari", string.Empty, new Platform(PlatformType.Any));
         }