Tweak of prereqs describing needs for Firefox

Author: sschwartzman

README.md

@@ -29,9 +29,9 @@ This formatter plugin is tested and compatible with the old version of Se-Builde
 ### Install the prerequisites
 
 1. Download & install either Se-builder v2 or v3:
-   * [se-builder 2](http://www.saucelabs.com/addons/selenium-builder-latest.xpi).
+   * [Firefox ESR 52](https://www.mozilla.org/en-US/firefox/organizations/) or the last pre-quantum release, [Firefox 56](https://archive.mozilla.org/pub/firefox/releases/56.0.2/). **Selenium Builder is currently not compatible with Firefox Quantum (Firefox 57+)**
+   * [Se-builder 2](http://www.saucelabs.com/addons/selenium-builder-latest.xpi).
    * [Selenium Builder 3](https://addons.mozilla.org/en-GB/firefox/addon/selenium-builder/)
-   * You'll need [FireFox ESR 52](https://www.mozilla.org/en-US/firefox/organizations/). Selenium Builder is currently not compatible with Firefox Quantum (Firefox 60)
 2. Run Se-builder at least once before proceeding. Running it the first time creates the folder where you'll put the plugin. Run it by going to <b>Tools > Web Developer > Launch Selenium Builder.</b>
 
 ### Install the plugin