Update Python CHANGES doc
For both 3.1 and 3.2
+Selenium 3.2.0
+* No major changes to Python bindings
+
+Selenium 3.1.0
+* Fix python HTTPS encoding for python driver (#3379)
+* Allow Firefox preferences to be set directly in Options
+* Fix shutdown and process termination (#3263)
+* Preventing exception if log_path is none or empty. Fixes #3128
+
Selenium 3.0.2
* Add support for W3C Get Active Element
* Return when we use executeScript for faking WebElement.get_property
