Add configuration parameters for Zombie.js driver

In the attached commit, I added three configuration parameters to the extension. These parameters are used to configure the used `ZombieServer`. 

In my current use case, I wanted to install zombie.js in my project's node_modules directory, not globally. To be able to use this zombie.js installation, I need to be able to configure the `node_modules_path` option of `ZombieServer`.