Update CHANGELOG.md

Author: normj

CHANGELOG.md

@@ -1,4 +1,7 @@
-### 3.0.0.0 (2021-07-06)
+### 3.0.1 (2021-07-06)
+* Pull request [#223](https://github.com/aws/aws-aspnet-cognito-identity-provider/pull/223) Fix UTC time conversion. Thanks [Joseph Fergusson](https://github.com/PhonicCanine)
+
+### 3.0.0 (2021-07-06)
 * Add target framework .NET Core 3.1
 * Remove target framework .NET Core 3.0