Role fails to unpack node_exporter binary

[filippo-form3]

What happened?
Role fails to unpack node_exporter binary because of file permissions.

Maybe related to this security fix in ansible: ansible/ansible#67794

Did you expect to see some different?
I was expecting the installation to succeed as with previous versions of ansible.

How to reproduce it (as minimally and precisely as possible):
Use version of ansible = 2.9.12.

Environment

• Role version:

  0.21.3

• Ansible version information:

  2.9.12

• Variables:

insert role variables relevant to the issue

• Ansible playbook execution Logs:

    qemu: TASK [node-exporter : Download node_exporter binary to local folder] ***********
    qemu: changed: [localhost]
==> qemu: [WARNING]: File '/tmp/node_exporter-1.0.1.linux-amd64.tar.gz' created with
==> qemu: default permissions '600'. The previous default was '666'. Specify 'mode' to
==> qemu: avoid this warning.
    qemu:
    qemu: TASK [node-exporter : Unpack node_exporter binary] *****************************
    qemu: fatal: [localhost]: FAILED! => {"changed": false, "msg": "an error occurred while trying to read the file '/tmp/node_exporter-1.0.1.linux-amd64.tar.gz': [Errno 13] Permission denied: '/tmp/node_exporter-1.0.1.linux-amd64.tar.gz'"}

[fprojetto]

Proposed fix: #178