Force Ansible 2.x compatiblity mode in Vagrant

In some setups it miss-detects the Ansible version and uses 1.8
compatiblity mode, which doesn't work properly with modern Ansible.

vagrant/lib/forklift/box_distributor.rb

@@ -190,6 +190,7 @@ def configure_ansible(machine, ansible, box_name)
 
       [playbooks].flatten.each_with_index do |playbook, index|
         machine.vm.provision("main#{index}", type: 'ansible') do |ansible_provisioner|
+          ansible_provisioner.compatibility_mode = '2.0'
           ansible_provisioner.playbook = playbook
           ansible_provisioner.extra_vars = ansible['variables']
           ansible_provisioner.groups = @ansible_groups