##### SUMMARY
hall module:  the hall.com is not available
```
 19 description:
 20     - "The C(hall) module connects to the U(https://hall.com) messaging API and allows you to deliver notication messages to rooms."
...
 24   room_token:
 25     description:
 26       - "Room token provided to you by setting up the Ansible room integation on U(https://hall.com)"
...
 65 HALL_API_ENDPOINT = 'https://hall.com/api/1/services/generic/%s'
```
It looks like https://hall.com is not available
```
test:~$ ping hall.com
ping: hall.com: No address associated with hostname
test:~$ ping www.hall.com
ping: www.hall.com: Name or service not known
test:~$ host hall.com
hall.com mail is handled by 10 mxa.mailgun.org.
hall.com mail is handled by 20 mxb.mailgun.org.
test:~$ host www.hall.com
Host www.hall.com not found: 3(NXDOMAIN)
```
I can't find any information about this service exists nowadays or not

Therefore, the module must be removed or fixed.

##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
```lib/ansible/modules/notification/hall.py```

##### ANSIBLE VERSION
```
2.8
```
description:
      - The title of the message
    required: true
  picture:
    description:
      - >
        The full URL to the image you wish to use for the Icon of the message. Defaults to
        U(http://cdn2.hubspot.net/hub/330046/file-769078210-png/Official_Logos/ansible_logo_black_square_small.png?t=1421076128627)
    required: false
"""
EXAMPLES = """
- name: Send Hall notifiation
  hall:
    room_token: <hall room integration token>
    title: Nginx
    msg: 'Created virtual host file on {{ inventory_hostname }}'
  delegate_to: loclahost
- name: Send Hall notification if EC2 servers were created.
  hall:
    room_token: <hall room integration token>
    title: Server Creation
    msg: 'Created instance {{ item.id }} of type {{ item.instance_type }}.\\nInstance can be reached at {{ item.public_ip }} in the {{ item.region }} region.'
  delegate_to: loclahost
  when: ec2.instances|length > 0
  with_items: '{{ ec2.instances }}'
"""
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.urls import fetch_url
HALL_API_ENDPOINT = 'https://hall.com/api/1/services/generic/%s'
def send_request_to_hall(module, room_token, payload):