Terraform dynamic inventory 0.12.12 (#5298)

* Update parsing of terraform state file for 0.12.12

* Resource does not seem to have a module element but instead has
provider
* Return the boolean right way if it is already a bool since a bool does
not have an lower method

* Remove the setting of ansible_ssh_user to root for all Packet

Not all servers in packet are accessed as root by default. CoreOS
systems use the `core` user. Removing this allows the user to specify
the remote user with an extra_var or in an ansible.cfg file.

* Default to root user for packet devices except on CoreOS

* Update TF_VERSION for packet in tf-validate-packet

Update TV_VERSION to 0.12.12 for gitlab-ci tf-validate-packet tests

* convert packet terraform files to TV_VERSION 4

* initalize terraform before copying the variable file to the top level dir

contrib/terraform/packet/variables.tf

@@ -54,3 +54,4 @@ variable "number_of_etcd" {
 variable "number_of_k8s_nodes" {
   default = 0
 }
+