Install Node.js. https://nodejs.org/en/download/.
Install Discord.io by using npm install discord.io winston --save in the Command Prompt (Windows)/Terminal (MacOS), and install Discord.js using npm install discord.js.
Linux? Use npm install --save discord.js
Navigate to the bot by using cd <filepath>.
Run this using node TestBot.js
If node outputs an error that includes .DS_storeand you're on MacOS or Linux, navigate to the folder (usually in ~/user/<username>/Downloads, unless youve moved it) and use find . -name .DS_Store -type f -delete.
Thanks to @poleroyd for the testing!