Fixed NTP test working dir.

tests/test_ntp.py

@@ -15,6 +15,8 @@ if 'remote' not in ntpd_status:
 else:
     print('System is NTP synchronized')
 
+os.chdir(os.path.dirname(__file__))
+
 print('Checking NTP server conforms to conf')
 if os.path.isfile('../utils.py'):
     es_utils = imp.load_source('es_utils', '../utils.py')