Fixes #2710 -- silence a deprecation warning.

Use the new name and alias to the old one
diff --git a/src/cryptography/x509/__init__.py b/src/cryptography/x509/__init__.py
index a1deb7f..787f1a6 100644
--- a/src/cryptography/x509/__init__.py
+++ b/src/cryptography/x509/__init__.py
@@ -4,6 +4,7 @@
 
 from __future__ import absolute_import, division, print_function
 
+from cryptography import utils
 from cryptography.x509.base import (
     Certificate, CertificateBuilder, CertificateRevocationList,
     CertificateRevocationListBuilder,
@@ -30,12 +31,19 @@
 )
 from cryptography.x509.name import Name, NameAttribute
 from cryptography.x509.oid import (
-    AuthorityInformationAccessOID, CRLEntryExtensionOID, CRLExtensionOID,
+    AuthorityInformationAccessOID, CRLEntryExtensionOID,
     CertificatePoliciesOID, ExtendedKeyUsageOID, ExtensionOID, NameOID,
     ObjectIdentifier, SignatureAlgorithmOID, _SIG_OIDS_TO_HASH
 )
 
 
+CRLExtensionOID = utils.deprecated(
+    CRLEntryExtensionOID,
+    __name__,
+    "CRLExtensionOID has been renamed to CRLEntryExtensionOID",
+    utils.DeprecatedIn12
+)
+
 OID_AUTHORITY_INFORMATION_ACCESS = ExtensionOID.AUTHORITY_INFORMATION_ACCESS
 OID_AUTHORITY_KEY_IDENTIFIER = ExtensionOID.AUTHORITY_KEY_IDENTIFIER
 OID_BASIC_CONSTRAINTS = ExtensionOID.BASIC_CONSTRAINTS