Unsafe use of eval

In file lib/utils/sea.js, the following use of eval is dangerous: 

``` js
    if (configSource) {
        configData = eval('(' + configSource + ')');
    }
```

The config file can be used to inject arbitrary commands. Either validate the content of the file, use JSON.parse or use a more advanced sanitization package like: 
https://www.npmjs.com/package/eval-sanitizer
