Trailing slashes on full URLs for repos that do not use ref

[nuest]

Zenodo and Figshare (and possibly other repos) do not use the ref, leading to a trailing slash in the generated URL, e.g.

http://localhost:8585/v2/zenodo/10.5281/zenodo.3242074/

Do we want to remove that? Could be done in function v2url(..) in binderhub/static/js/index.js.

I'm in the "remove" corner, thinking of a URL ending / as a directory. Here's some wisdom by others:

• https://stackoverflow.com/questions/5948659/when-should-i-use-a-trailing-slash-in-my-url
• https://blog.papercut.com/trailing-slashes-on-your-urls-to-be-or-not-to-be-is-it-a-question/
• https://www.cloudways.com/blog/trailing-slashes-urls/

(Or should we use the ref to identify the version or a record? Don't think r2d transparently supports this right now.)

[betatim]

I don't have a strong opinion on this. Without a trailing slash looks nicer, but I have to admit I hardly ever look/pay attention to this.

We should make sure that were possible we are forgiving to users and accept with and without trailing slash where possible. The number of hours I've spent staring at two seemingly equal URLs (where one worked and the other didn't) to help a user who had added/removed a / is far too big.