Update changelog

Author: OndraM

CHANGELOG.md

@@ -5,6 +5,13 @@ This project versioning adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 - `WebDriverCheckboxes` and `WebDriverRadios` helper classes to simplify interaction with checkboxes and radio buttons.
 
+### Fixed
+- Stop sending null values in Cookie object, which is against the protocol and may cause request to remote ends to fail.
+
+### Changed
+- Force Chrome to not use W3C WebDriver protocol.
+- Add workaround for Chromedriver bug [2943](https://bugs.chromium.org/p/chromedriver/issues/detail?id=2943) which breaks the protocol in Chromedriver 75.
+
 ## 1.6.0 - 2018-05-16
 ### Added
 - Connection and request timeouts could be specified also when creating RemoteWebDriver from existing session ID.