wordpress-nginx-rhel7 linted and updated

[RayJin2000]

I tried to update the old Wordpress with nginx examples, to adhere to the standards of the Ansible linter. - Issue 322:

moved wordpress-nginx to wordpress-nginx_rhel6

• This examples are too old an should be removed

updatet wordpress-nginx_rhel7:

• command-instead-of-shell
• command-instead-of-module
• deprecated-local-action
• fqcn
• key-order
• no-free-form
• no-jinja-when
• yaml
• empty-string-compare
• deprecated-local-action
• risky-file-permissions
• name
• Updated Packages and Keys
• no more with_items