Issue #88 - Update Firefox to version 60.0

* Updated the README file

Author: ppodgorsek

README.md

@@ -18,7 +18,7 @@ The versions used in the latest version are:
 * [Robot Framework](https://github.com/robotframework/robotframework) 3.0.4
 * [Robot Framework Faker](https://github.com/guykisel/robotframework-faker) 4.2.0
 * [Robot Framework SeleniumLibrary](https://github.com/robotframework/SeleniumLibrary) 3.1.1
-* Firefox 59.0
+* Firefox 60.0
 * Chromium 65.0
 
 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.