Add non-intrusive support for AWS to Vagrantfile

This changeset adds support for AWS provisioning to
Vagrantfile. It won't get in the way of regular users
who want to just use Virtualbox.

The AWS provider will be required only if the user does:

vagrant up --provider=aws

deployment/Vagrantfile

@@ -21,4 +21,20 @@ Vagrant.configure("2") do |config|
   config.vm.provider :parallels do |prl, override|
     override.vm.box = "parallels/ubuntu-12.04"
   end
+
+  config.vm.provider :aws do |aws, override|
+    aws.ami = ENV['AWS_AMI'] || "ami-828675f5"
+    aws.region = ENV['AWS_REGION'] || "eu-west-1"
+    aws.instance_type = "t1.micro"
+
+    override.vm.box = "dummy"
+    override.vm.box_url = "https://github.com/mitchellh/vagrant-aws/raw/master/dummy.box"
+    override.ssh.private_key_path = ENV["AWS_SSH_PRIVKEY"]
+    override.ssh.username = ENV['AWS_SSH_USER'] || "ubuntu"
+
+    aws.access_key_id = ENV["AWS_ACCESS_KEY_ID"]
+    aws.secret_access_key = ENV["AWS_SECRET_ACCESS_KEY"]
+    aws.keypair_name = ENV["AWS_KEYPAIR_NAME"]
+    aws.security_groups = [ ENV["AWS_SECURITY_GROUP"] ]
+  end
 end