title: The type or namespace name 'IWebDriver' could not be found error while executing Nunit test through Selenium on Visual Studio 2017
body: <p>I am trying to create some test cases with selenium on a mac with C#. The IDE I am using is visual studio 2017. I have the following packages installed , selenium web driver, selenium support, selenium firefox web driver. My Question is how do I successfully use selenium to create test cases for website using C#. Whenever I try to run the test cases, the following errors pop up ;</p>
  
  <pre><code>/Users/andrew/Projects/test/test/Test.cs(23,23): Error CS0234: The type or namespace name 'Firefox' does not exist in the namespace 'OpenQA.Selenium' (are you missing an assembly reference?) (CS0234) (test)      
  </code></pre>
  
  <p>and</p>
  
  <pre><code>/Users/andrew/Projects/test/test/Test.cs(9,9): Error CS0246: The type or namespace name 'IWebDriver' could not be found (are you missing a using directive or an assembly reference?) (CS0246) (test)
  </code></pre>
  
  <p>Code trial:    </p>
  
  <pre><code>using NUnit.Framework;
  using System;
  using OpenQA.Selenium;
  using OpenQA.Selenium.Firefox;
  namespace test
  {
      [TestFixture()]
      public class Test
      {
  
          IWebDriver driverOne = new FirefoxDriver();
  
          [Test()]
          public void TestCase()
          {
              driverOne.Navigate().GoToUrl("http://google.com/");
          }
      }
  }
  </code></pre>