Issue #165 - Update Firefox to version 67.0

* Updated the README

Author: ppodgorsek

README.md

@@ -20,7 +20,7 @@ The versions used are:
 * [Robot Framework Pabot](https://github.com/mkorpela/pabot) 0.53
 * [Robot Framework Requests](https://github.com/bulkan/robotframework-requests) 0.5.0
 * [Robot Framework SeleniumLibrary](https://github.com/robotframework/SeleniumLibrary) 3.3.1
-* Firefox 66.0
+* Firefox 67.0
 * Chromium 73.0
 
 As stated by [the official GitHub project](https://github.com/robotframework/Selenium2Library), starting from version 3.0, Selenium2Library is renamed to SeleniumLibrary and this project exists mainly to help with transitioning. The Selenium2Library 3.0.0 is also the last release and for new releases, please look at the [SeleniumLibrary](https://github.com/robotframework/SeleniumLibrary) project.