Got the port forwarding working.

Chrome considers 6666 a dangerous port. 💩

vagrant_linux_dev_env/Vagrantfile

@@ -9,7 +9,7 @@ Vagrant.configure("2") do |config|
   # Every Vagrant virtual environment requires a box to build off of.
   config.vm.box = "precise32"
   config.vm.provision :shell, :path => "bootstrap.sh"
-  config.vm.network :forwarded_port, host: 6666, guest: 80
+  config.vm.network :forwarded_port, host: 8080, guest: 80
 
   # The url from where the 'config.vm.box' box will be fetched if it
   # doesn't already exist on the user's system.