actually disable stdout/stderr. stdout>stderr (#1321)

* actually disable stdout/stderr. stdout>stderr

* for pure runner this turns it off for real this time.
* this also just makes the agent container type send stdout to stderr, since
we're not using stdout for function output anymore this is pretty
straightforward hopefully.
* I added a panic and some type checking printlns to ensure this is true for
pure_runner, both stdout and stderr are off, also added a unit test from agent
to ensure this behavior from its container type, which pure_runner utilizes
(no integration test though)
* tests ensure that logs still work if not trying to disable them (full agent)

* handle non ghost swapping

api/server/apps_test.go

@@ -325,7 +325,6 @@ func TestAppUpdate(t *testing.T) {
 			}
 
 			if test.expectedError != nil {
-				fmt.Printf("resp: %s", rec.Body)
 				resp := getErrorResponse(t, rec)
 
 				if !strings.Contains(resp.Message, test.expectedError.Error()) {