Fixing commit history from old changelog PR

http://github.com/cloudevents/sdk-python/pull/48

Signed-off-by: Curtis Mason <cumason@google.com>

Author: Curtis Mason

CHANGELOG.md

@@ -4,6 +4,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.0.0]
+### Added
+- Added a user friendly CloudEvent class with data validation ([#36])
+- CloudEvent structured cloudevent support ([#47])
+
+### Removed
+- Removed support for Cloudevents V0.2 and V0.1 ([#43])
+
 ## [0.3.0]
 ### Added
 - Added Cloudevents V0.3 and V1 implementations ([#22])
@@ -65,4 +73,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#22]: https://github.com/cloudevents/sdk-python/pull/22
 [#23]: https://github.com/cloudevents/sdk-python/pull/23
 [#25]: https://github.com/cloudevents/sdk-python/pull/25
-[#27]: https://github.com/cloudevents/sdk-python/pull/27
+[#27]: https://github.com/cloudevents/sdk-python/pull/27
+[#36]: https://github.com/cloudevents/sdk-python/pull/36
+[#43]: https://github.com/cloudevents/sdk-python/pull/43
+[#47]: https://github.com/cloudevents/sdk-python/pull/47