All variables should start with acmesh_

This is going to need backwards compatibility but in the future these variables:

# Set this to the commonName for the cert
common_name: "{{ inventory_hostname }}"
# Array for the subjectAltNames, this should include the commonName
subject_alt_names:
  - "{{ inventory_hostname }}"
  - "www.{{ inventory_hostname }}"
# Get an ECC cert
ecc: true
# Set this to the directory for the certs
le_dir: /etc/ssl/le
# Set this to the DocumentRoot for /.well-known/acme-challenge
document_root: /var/www/html

Should be changed to:

# Set this to the commonName for the cert
acmesh_common_name: "{{ inventory_hostname }}"
# Array for the subjectAltNames, this should include the commonName
acmesh_subject_alt_names:
  - "{{ inventory_hostname }}"
  - "www.{{ inventory_hostname }}"
# Get an ECC cert
acmesh_ecc: true
# Set this to the directory for the certs
acmesh_le_dir: /etc/ssl/le
# Set this to the DocumentRoot for /.well-known/acme-challenge
acmesh_document_root: /var/www/html