taking out ansible.inventory, not needed for vagrant, breaks my vagrant provisioning

vagrant/base/devstack/Vagrantfile

@@ -52,7 +52,6 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
   config.vm.provision :ansible do |ansible|
     ansible.playbook = "../../../playbooks/vagrant-devstack.yml"
-    ansible.inventory_path = "../../../playbooks/vagrant/inventory.ini"
     ansible.verbose = "extra"
   end
 end

vagrant/base/fullstack/Vagrantfile

@@ -28,7 +28,6 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   config.vm.provision :ansible do |ansible|
     # point Vagrant at the location of your playbook you want to run
     ansible.playbook = "../../../playbooks/vagrant-fullstack.yml"
-    ansible.inventory_path = "../../../playbooks/vagrant/inventory.ini"
     ansible.verbose = "extra"
   end
 end