DBTest.cs

public class DBTest : IDisposable
{
  private DataContext dataContext;

  public DBTest()
  {
    dataContext = new DataContext();
  }

  public void Dispose()
  {
    if (dataContext != null)
      dataContext.Dispose();
  }

  public void StartDBTest()
  {
    DeleteDatabaseIfExists();
    CreateDatabase();
    RunFixtures();
  }

  public void EndDBTest()
  {
    DeleteDatabaseIfExists();
  }

  private void DeleteDatabaseIfExists()
  {
    if (dataContext.Database.Exists)
      dataContext.Database.Delete();
  }

  private void CreateDatabase()
  {
    dataContext.Database.CreateDatabase();
  }

  private void RunFixtures()
  {
    // Here, put any inserts that need to happen. In most
    // scenarios, a completely empty database just will not
    // work. You have to expect some basic amount of data.
  }
}

DBTestContext

public abstract class DBTestContext
{
  protected DBTest dbTest;

  [TestFixtureSetUp]
  public virtual void BeforeAllTests()
  {
    using (dbTest = new DBTest())
    {
      dbTest.StartDBTest();
    }
  }

  [SetUp]
  public virtual void BeforeEachTest()
  {
    dbTest = new DBTest();
  }

  [TearDown]
  public virtual void AfterEachTest()
  {
    if (dbTest != null)
     dbTest.Dispose();
  }

  [TestFixtureTearDown]
  public virtual void AfterAllTests()
  {
    using (dbTest != null)
    {
      dbTest.EndDBTest();
    }
  }
}

SampleTest.cs

public class SampleTest : DBTestContext
{
  public override void BeforeEachTest()
  {
    // Code here will be run before each test.
    base.BeforeEachTest();
  }

  public override void AfterEachTest()
  {
    // Code here will be run after each test.
    base.AfterEachTest();
  }

  [Test]
  public void TestThatRecordIsInserted()
  {
    // Depending on how many other tests you have, and what order they're run
    // we cannot guarantee that the Employees table is empty.
    int initialCount = dataContext.Employees.Count();

    dataContext.Employees.Add(new Employee { FirstName = John, LastName = Doe });
    dataContext.SaveAllChanges();

    int newCount = dataContext.Employees.Count();
    Assert.Equal(newCount, initialCount + 1);
    // This is why your tests have to be single threaded. What if you have two tests
    // performing inserts, and just by chance they run in such a way that this test
    // breaks. You could test newCount > initialCount, but that's not as specific.
  }
}