removed unused imports

Author: shbenzer

examples/dotnet/SeleniumDocs/SeleniumManager/UsageTest.cs

@@ -1,10 +1,4 @@
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Linq;
-using OpenQA.Selenium;
-using OpenQA.Selenium.Support.UI;
 using OpenQA.Selenium.Chrome;
 
 namespace SeleniumDocs.Support