* Add acme library usage example
Create, edit and deactivate account.
Setup and perform http-01 challenge.
Issue, renew and revoke certificate.
* Adapt example to ACME-v2 and exclude data persistence
The code to persist/load data would length this example and distract from what is actually important.
* Fix domain names and e-mail addresses
* Remove unnecessary license header
This usage example is under the license for the acme package.
* Remove logging information
The code will be mostly read by developers, so simplify the logging info into comments.
* Revert abstraction of simple methods
All methods that are used only once in this example were expanded into the main code in order to make the process more explicit.
* Fix missing URL suffix
* Improve aesthetics and reorganize workflow
Also make words capitalization consistent and improve comments.
No complaints from pep8.
