For anyone else, I forgot to link the guide I was following... here. But what I eventually read on SO was I needed to add the files myself as rails didn't create them. So I manually added the following:
Well I had followed this guide (unless I missed a step I'm unaware of) and ran the following commands
• bundle update rails
• rails app:update
Which did perform updates to files in my bin/ and config/ directories. What is the actual helper method you are referring to for "rails upgrade"? I tried running that in my terminal but it error'd out so I'm guessing that it wasn't meant for there. I'll leave the error below in case it was intended for there.
No, I mis-remembered the name, you found the thing I was thinking of. I'm not sure why the update script didn't make the missing files. But glad you found the way to get them in there.