chore: Prepare for 3.10.0 Release (#359)

Summary
-------
-  Prepare for 3.10.0 Release

Author: The-inside-man

Diff for: CHANGELOG.md

@@ -1,5 +1,23 @@
 # Optimizely Python SDK Changelog
 
+## 3.10.0
+September 16th, 2021
+
+### New Features
+* Added new public properties to OptimizelyConfig. 
+  - sdk_key and environment_key [#338] (https://github.com/optimizely/python-sdk/pull/338)
+  - attributes and events [#339] (https://github.com/optimizely/python-sdk/pull/339)
+  - experiment_rules, delivery_rules, audiences and audiences in OptimizelyExperiment 
+    - [#342] (https://github.com/optimizely/python-sdk/pull/342)
+    - [#351] (https://github.com/optimizely/python-sdk/pull/351/files)
+* For details please refer to our documentation page:
+  - Python-sdk: [https://docs.developers.optimizely.com/full-stack/docs/optimizelyconfig-python]
+
+* OptimizelyFeature.experiments_map of OptimizelyConfig is now deprecated. Please use OptimizelyFeature.experiment_rules and OptimizelyFeature.delivery_rules. [#360] (https://github.com/optimizely/python-sdk/pull/360)
+
+### Bug Fixes
+* Fix event processor negative timeout interval when retrieving events from queue. [#356] (https://github.com/optimizely/python-sdk/pull/356)
+
 ## 3.9.1
 July 14th, 2021
 

Diff for: optimizely/version.py

@@ -11,5 +11,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-version_info = (3, 9, 1)
+version_info = (3, 10, 0)
 __version__ = '.'.join(str(v) for v in version_info)