Add Retry-After header value to get renewal info result about lego HOT 3 CLOSED

Maybe I wasn't clear enough. By "the Lego library doesn't account for that" I meant that the library part of the project (as opposed to the command line tool), specifically the GetRenewalInfo method, ignores the header value. This diff fixes that. It is up to whoever implements the library to decide if and how to use the newly provided value. In my case, I can use it in my custom-made service to set the next time when to rerun the renewal check process.
If I'm understood now and we agree on the issue, can I begin with a PR?

from lego.

Hello,

The only constraint for a client is to follow suggestedWindow (MUST).
The support Retry-After is recommended (SHOULD) but not required.

Your patch gets the Retry-After information but doesn't use it.

You can open a PR, you will have to add the missing elements.

Note: please use " for string, and explicit field name inside tests.

from lego.

ok, let's go for a PR.

from lego.