Reorganize tests

- Pester source code moved to `test/Pester`, deleted `ext-src`.
- Pester tests (.ps1 files) moved to `test/powershell`
- xUnit tests (.cs files) moved to `test/csharp`
- Third-party script test moved to `test/shebang`

test/powershell/Remove-Event.Tests.ps1

@@ -0,0 +1,38 @@
+Describe "Remove-Event" {
+
+    BeforeEach{
+	    New-Event -sourceidentifier PesterTimer  -sender windows.timer -messagedata "PesterTestMessage" 
+    }
+
+    AfterEach{
+            Remove-Event -sourceidentifier PesterTimer -ErrorAction SilentlyContinue 
+     }
+    
+    Context "Check Remove-Event can validly remove events" {
+
+        It "Should remove an event given a sourceidentifier" {
+	    { Remove-Event -sourceidentifier PesterTimer } 
+            { Get-Event -ErrorAction SilentlyContinue | Should Not Contain PesterTimer }
+  	}
+
+        It "Should remove an event given an event identifier" {
+            { $events = Get-Event -sourceidentifier PesterTimer }
+	    { $events = $events.EventIdentifier }
+	    { Remove-Event -EventIdentifier $events }
+            { $events = Get-Event -ErrorAction SilentlyContinue}
+	    { $events.SourceIdentifier | Should Not Contain "PesterTimer" }
+	}
+
+	It "Should be able to remove an event given a pipe from Get-Event" {
+	    { Get-Event -sourceidentifier PesterTimer | Remove-Event }
+	    { Get-Event -ErrorAction SilentlyContinue | Should Not Contain "PesterTimer" } 
+
+	}
+
+	It "Should NOT remove an event given the whatif flag" {
+            { Remove-Event -sourceidentifier PesterTimer -whatif }
+            { $events = Get-Event }
+            { $events.SourceIdentifier  | Should Contain "PesterTimer" }
+	}
+    }
+}