This commit introduces a new module called vr_firewall_group_facts.
This module aims to return the list of firewall groups avaiable
avaiable in Vultr.
Sample available here:
```
"vultr_firewall_group_facts": [
{
"date_created": "2018-07-17 12:22:51",
"date_modified": "2018-07-17 12:24:47",
"description": "ansible-firewall-group",
"id": "fb5a0876",
"instance_count": 0,
"max_rule_count": 50,
"rule_count": 1
}
]
```
