Fix Terraform version check

[hectcastro]

Ensure that this role installs the version of Terraform defined in terraform_version when it is not currently installed.

Also, update the default version of Terraform to 0.7.5.

---

Testing

First, compare the versions of Molecule and Ansible you have installed to these:

❯ molecule --version
molecule, version 1.12.4

❯ ansible --version
ansible 2.1.2.0
  config file = /Users/hcastro/Projects/ansible-terraform/ansible.cfg
  configured module search path = Default w/o overrides

Next, converge across both platforms:

❯ molecule converge --platform=all

Then, change the version of Terraform to be installed:

diff --git a/defaults/main.yml b/defaults/main.yml
index c4a2a98..db30e75 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -1,2 +1,2 @@
 ---
-terraform_version: "0.7.5"
+terraform_version: "0.7.4"

Lastly, converge again and login to ensure that the correct version of Terraform is installed:

❯ molecule converge --platform=all

❯ molecule login --host ansible-terraform-trusty64
Warning: Permanently added '[127.0.0.1]:2222' (ECDSA) to the list of known hosts.
Welcome to Ubuntu 14.04.5 LTS (GNU/Linux 3.13.0-96-generic x86_64)

 * Documentation:  https://help.ubuntu.com/

  System information as of Mon Oct 10 15:09:24 UTC 2016

  System load:  0.01              Processes:           86
  Usage of /:   3.9% of 39.34GB   Users logged in:     0
  Memory usage: 27%               IP address for eth0: 10.0.2.15
  Swap usage:   0%

  Graph this data and manage this system at:
    https://landscape.canonical.com/

  Get cloud support with Ubuntu Advantage Cloud Guest:
    http://www.ubuntu.com/business/services/cloud

New release '16.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.


Last login: Mon Oct 10 15:10:05 2016 from 10.0.2.2
vagrant@ansible-terraform-trusty64:~$ terraform --version
Terraform v0.7.4

Your version of Terraform is out of date! The latest version
is 0.7.5. You can update by downloading from www.terraform.io

❯ molecule login --host ansible-terraform-xenial64
Warning: Permanently added '[127.0.0.1]:2200' (ECDSA) to the list of known hosts.
Welcome to Ubuntu 16.04.1 LTS (GNU/Linux 4.4.0-34-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  Get cloud support with Ubuntu Advantage Cloud Guest:
    http://www.ubuntu.com/business/services/cloud

71 packages can be updated.
32 updates are security updates.


Last login: Mon Oct 10 15:10:05 2016 from 10.0.2.2
ubuntu@ansible-terraform-xenial64:~$ terraform --version
Terraform v0.7.4

Your version of Terraform is out of date! The latest version
is 0.7.5. You can update by downloading from www.terraform.io

[tnation14]

Tested with molecule 1.12.4, ansible 2.1.2.0, everything looks good 👍

Converge works the first time...

$ molecule converge
TASK [ansible-terraform : Check Terraform Version] *****************************
ok: [ansible-terraform-trusty64]
ok: [ansible-terraform-xenial64]

TASK [ansible-terraform : Download Terraform] **********************************
changed: [ansible-terraform-trusty64]
changed: [ansible-terraform-xenial64]

TASK [ansible-terraform : Extract and install Terraform] ***********************
changed: [ansible-terraform-xenial64]
>f++++++.?? terraform
changed: [ansible-terraform-trusty64]
>f++++++.?? terraform

PLAY RECAP *********************************************************************
ansible-terraform-trusty64 : ok=8    changed=3    unreachable=0    failed=0
ansible-terraform-xenial64 : ok=9    changed=3    unreachable=0    failed=0

$ molecule login

vagrant@ansible-terraform-trusty64:~$ terraform -v
Terraform v0.7.5

Update terraform version:

diff --git a/defaults/main.yml b/defaults/main.yml
index c4a2a98..b59e173 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -1,2 +1,2 @@
 ---
-terraform_version: "0.7.5"
+terraform_version: "0.7.3"

converge works a second time:

$ molecule converge --platform=all

TASK [ansible-terraform : Check Terraform Version] *****************************
ok: [ansible-terraform-trusty64]
ok: [ansible-terraform-xenial64]

TASK [ansible-terraform : Download Terraform] **********************************
changed: [ansible-terraform-xenial64]
changed: [ansible-terraform-trusty64]

TASK [ansible-terraform : Extract and install Terraform] ***********************
changed: [ansible-terraform-xenial64]
.fcstp...?? terraform
changed: [ansible-terraform-trusty64]
.fcstp...?? terraform

PLAY RECAP *********************************************************************
ansible-terraform-trusty64 : ok=8    changed=2    unreachable=0    failed=0
ansible-terraform-xenial64 : ok=9    changed=2    unreachable=0    failed=0

$ molecule login

vagrant@ansible-terraform-trusty64:~$ terraform -v
Terraform v0.7.3

Your version of Terraform is out of date! The latest version
is 0.7.5. You can update by downloading from www.terraform.io