added log_path

nightwatch.json

@@ -10,7 +10,7 @@
         "start_process": true,
         "server_path": "./node_modules/.bin/chromedriver",
         "port": 9515,
-        "log_path": false
+        "log_path": "tests/browser/output"
       },
       "desiredCapabilities": {
         "browserName": "chrome"