pr_push() and / in branches

[romainfrancois]

I'm not sure how to create a reprex for this, so I'll explain. I'm trying to push into that pr: apache/arrow#3932

I was able to pr_fetch() on https, but then after making my commits, I can't push:

❯ pr_push()
✔ Checking that local branch 'javierluraschi-bugfix/port-win-fixes' has the changes in 'javierluraschi/bugfix/port-win-fixes'
Error: `rmref` must be of form 'remote/branch'.

It looks like the git_parse_remref does not want branch names with a /

❯ usethis:::git_parse_remref
function (remref) 
{
    remref_split <- strsplit(remref, "/")[[1]]
    if (length(remref_split) != 2) {
        ui_stop("{ui_code('rmref')} must be of form {ui_value('remote/branch')}.")
    }
    list(remote = remref_split[[1]], branch = remref_split[[2]])
}

Maybe instead, we could assume that a remote name won't have / so whatever is after the first / is the branch name ?