Add always to add_header and other http verbs in nginx config

[vp993]

By default, Nginx add_header directive does not work if HTTP status code is 40x or 50x. To make it work regardless status code, I added always at the end. Related to #106

Also, I added PUT, PATCH, and DELETE verbs to the Access-Control-Allow-Methods and a little bit refactored code.

Please let me know if you have any questions.

[ralph-tice]

This doesn't seem to have been tested -- you can't actually use || in an nginx if statement.

You can, however, use regex.

ex:

if ($request_method ~ '(POST|GET|PUT|PATCH|DELETE)' ) {