I've done everything I can to get internet explorer working with webdriver.io but there is one part that is very confusing. 

Step 1: Download internet explorer driver here: <http://www.seleniumhq.org/download/> (The file is a .exe and is called 'IEDriverServer.exe')

Step 2: No need to run the executable, just put it in an easily accessible folder and remember the path to that folder.

Step 3: Quoting from the documentation here: <https://github.com/SeleniumHQ/selenium/wiki/InternetExplorerDriver> 
This is what I need to do: 
"The standalone server executable must be downloaded from the Downloads page and placed in your PATH."

I see tons of info about how to do this in java, but nothing about how to do it in webdriver.io. Just editing the path in environment variables does not do the trick and it doesn't really make sense to do that.