Free Meteor Hosting - Change File Permissions

Hey guys, I have created a meteor project that uses Selenium Webdriver (a browser automator that runs in java). I call it using the child_process module:
var childProcess = Npm.require("child_process"); var args = ["-jar", "selenium-server-standalone.jar", '"chromedriver"'] childProcess.spawn("java", args)

In the development environment, the code runs. However when I deploy it to Meteor’s free server, the following occurs:
1-) Selenium Webdriver is executed by Java.
2-) Selenium Webdriver tries to execute chromedriver, but it’s blocked. The following log message is generated:

RuntimeError: The driver is not executable

I believe this is an error caused by chromedriver permissions, so I’d like to know if there’s any way of changing the chmod options on the free server.

Thanks for the help!