Update config.rb

I've set development_mode to false, but at some point we should remove all references to development_mode. We received an email from Vero:

"As you know, we recently pushed live a new UI for Vero.

One core change in this UI moving forward is the introduction of our Projects feature as a means of managing multiple environments. All customers will get two Projects included in every plan, allowing you to setup a Live and Staging environment that have separate API keys.

When we push the new UI live for all customers next week, we will no longer support the old development_mode flag. 

You currently use this flag and, in order to get setup correctly with the new setup (which you can do immediately) you need to follow three simple steps:

1. Grab your new API Key for the 'Test' project from your Account settings area (we created this new project for you) 

2. Remove the reference to development_mode in the init block:
_veroq.push(['init', { api_key: "YOUR_API_KEY", development_mode: true}]);
should become:
_veroq.push(['init', { api_key: "YOUR_API_KEY"}]);

3. Replace the API Key in your test environment to use the new API Key from your 'test' project."