Add constants with Let's Encrypt directories urls

Author: tkukushkin

src/aioacme/__init__.py

@@ -1,4 +1,5 @@
 from aioacme._client import Client
+from aioacme._directories import LETS_ENCRYPT_DIRECTORY, LETS_ENCRYPT_STAGING_DIRECTORY
 from aioacme._exceptions import AcmeError
 from aioacme._models import (
     Authorization,
@@ -16,6 +17,10 @@
 from aioacme._version import __version__, __version_tuple__
 
 __all__ = [
+    'Client',
+    'LETS_ENCRYPT_DIRECTORY',
+    'LETS_ENCRYPT_STAGING_DIRECTORY',
+    'AcmeError',
     'Authorization',
     'AuthorizationStatus',
     'Challenge',
@@ -27,8 +32,6 @@
     'Order',
     'OrderStatus',
     'RevocationReason',
-    'AcmeError',
-    'Client',
     '__version__',
     '__version_tuple__',
 ]

src/aioacme/_client.py

@@ -13,6 +13,7 @@
 from cryptography import x509
 from cryptography.hazmat.primitives import serialization
 
+from aioacme._directories import LETS_ENCRYPT_STAGING_DIRECTORY
 from aioacme._exceptions import AcmeError
 from aioacme._jwk import JWK, jwk_thumbprint, make_jwk
 from aioacme._jws import jws_encode
@@ -40,7 +41,7 @@ def __init__(
         self,
         *,
         account_key: PrivateKeyTypes,
-        directory_url: str = 'https://acme-staging-v02.api.letsencrypt.org/directory',
+        directory_url: str = LETS_ENCRYPT_STAGING_DIRECTORY,
         account_uri: str | None = None,
     ) -> None:
         """

src/aioacme/_directories.py

@@ -0,0 +1,2 @@
+LETS_ENCRYPT_DIRECTORY: str = 'https://acme-v02.api.letsencrypt.org/directory'
+LETS_ENCRYPT_STAGING_DIRECTORY: str = 'https://acme-staging-v02.api.letsencrypt.org/directory'