For anyone else still having problems!
Dropbox doesn't currently have an option to host websites
However the link Spacedoubt posted before about Google Drive does work now.
Here it is again: support.google.com/drive/answer/2881970?hl=en
1. Make sure the game folder is public
2. Open up your index.html by double clicking it
3. Copy the last part of the html (the part in bold here) --> drive.google.com/drive/u/0/?pli=1#folders/xxxxxxxxxxxxxxxxxxxxxxx
4.Now open a new tab and type --> [doc id]
[doc id] being the long set of numbers and letters you copied