chore: Prep for release 3.0.0

CHANGELOG.rst

@@ -2,6 +2,23 @@
 Changelog
 *********
 
+3.0.0 -- 2021-07-01
+===================
+
+Deprecation
+-----------
+The AWS Encryption SDK for Python no longer supports Python 2 or Python 3.4
+as of major version 3.x; only Python 3.5+ is supported. Customers using Python 2
+or Python 3.4 can still use the 2.x line of the AWS Encryption SDK for Python,
+which will continue to receive security updates for the next 12 months, in accordance
+with our `Support Policy <https://github.com/aws/aws-encryption-sdk-python/blob/master/SUPPORT_POLICY.rst>`__.
+
+Maintenance
+-----------
+* Move away from deprecated cryptography ``int_from_bytes``
+  `#355 <https://github.com/aws/aws-encryption-sdk-python/pull/355>`_
+
+
 2.4.0 -- 2021-07-01
 ===================
 

SUPPORT_POLICY.rst

@@ -26,12 +26,12 @@ This table describes the current support status of each major version of the AWS
       - End of Support
       - 2022-06-30
     * - 2.x
-      - General Availability 
       - Maintenance
-      - 2021-07-01
+      - End of Support
+      - 2022-07-01
     * - 3.x
-      - 
       - General Availability 
-      - 2021-07-01
+      -
+      -
 
 .. _AWS SDKs and Tools Maintenance Policy: https://docs.aws.amazon.com/sdkref/latest/guide/maint-policy.html#version-life-cycle

src/aws_encryption_sdk/identifiers.py

@@ -27,7 +27,7 @@
     # We only actually need these imports when running the mypy checks
     pass
 
-__version__ = "2.4.0"
+__version__ = "3.0.0"
 USER_AGENT_SUFFIX = "AwsEncryptionSdkPython/{}".format(__version__)