Updated Selenium tests (markdown)

Selenium-tests.md

@@ -1,10 +1,58 @@
 ## Running tests
 
+## Setting up Selenium with the Chromium webdriver:
+
+Instructions assume Ubuntu 16.04/16.10, but package managers for your distribution should have working distributions.
+
+1. Java runtime (`java`). 
+
+  The Oracle JVM can be installed with:
+
+  ```
+  apt install oracle-java8-installer
+  ```
+
+  Note: These instructions are incomplete if using OpenJDK.
+
+2. Selenium stand-alone server.
+
+  Obtain the standalone server from the [Selenium downloads page](http://docs.seleniumhq.org/download/).
+  
+  Using the current download link (as of Feb 2. 2017) to download it to your home directory:
+  
+  ```
+  wget https://goo.gl/Lyo36k -o ~/selenium-server-standalone.jar
+  ```
+
+3. Chromium webdriver.
+  
+  This will install the `chromedriver` binary to `/usr/lib/chromium-browser/chromedriver` on Ubuntu. Take note of the location of the binary if your package manager uses. 
+
+  ```
+  apt install chromium-chromedriver
+  ```
+
+4. (Optional) For headless operation, xvfb.
+  
+  The X virtual framebuffer will allow Chromium to run for tests on a server, this is not necessary if using a desktop with X or X forwarding.
+  
+  ```
+  apt install xvfb
+  ```
+  
+5. Launching Selenium.
+
+  The path to the `chromedriver` binary needs to be given when launching the server, as follows:
+  
+  ```
+  java -Dwebdriver.chrome.driver=/usr/lib/chromium-browser/chromedriver -jar ~/selenium-server-standalone.jar
+  ```
+  
 ### With Stack
 
-To run the full testsuite, do `stack test`. You'll need Selenium server running.
+Before running the test suite, you will need to launch Selenium and the server will run during tests.
 
-[TODO: describe how to get Selenium running]
+To run the full testsuite, do `stack test`. You'll need Selenium server running.
 
 ### From GHCi