Add Get-TraceSource test

test/powershell/Get-TraceSource.Tests.ps1

@@ -0,0 +1,6 @@
+Describe "Get-TraceSource" -tags "P1" {
+    It "Should output data sorted by name" {
+        $expected = (Get-TraceSource | Sort-Object Name)
+        Get-TraceSource | Should be $expected
+    }
+}