Fix broken test output produced by MakeFatalToPanic

The output from `MakeFatalToPanic` doesn't add a newline to the logged
entry, breaking the Go test output which expects final logged messages
to have their own newline.

helpers/fatal_panic.go

@@ -18,7 +18,7 @@ func (s *fatalLogHook) Levels() []logrus.Level {
 }
 
 func (s *fatalLogHook) Fire(e *logrus.Entry) error {
-	_, _ = fmt.Fprint(s.output, e.Message)
+	_, _ = fmt.Fprintln(s.output, e.Message)
 
 	panic(e)
 }