HealthChecker should print out error message when it fails

           if (process.exitValue() != 0) {
                String str;
                InputStream stdin = process.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(stdin));
                while ((str = reader.readLine()) != null) {
                    if (str.startsWith("ERROR")) {
                        LOG.warn("The healthcheck process {} exited with code {}", script, process.exitValue());
                        return FAILED;
                    }
                }
                return FAILED_WITH_EXIT_CODE;
            }