Merge pull request #2768 from reaperhulk/changelog-is-signature-valid

add changelog entry for is_signature_valid
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 9c43a83..0bbbcde 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -10,6 +10,8 @@
   ``cryptography`` 1.4.
 * Added support for the :class:`~cryptography.x509.PolicyConstraints` X.509
   extension.
+* Added :attr:`~cryptography.x509.CertificateSigningRequest.is_signature_valid`
+  to :class:`~cryptography.x509.CertificateSigningRequest`.
 * Fixed an intermittent ``AssertionError`` when performing an RSA decryption on
   an invalid ciphertext, ``ValueError`` is now correctly raised in all cases.