fs_add_authors sometimes adds wrong author

[cboettig]

As far as I can tell, this occurs when author does not have figshare profile?

Minimal examples:

id <- fs_create("test", "test description")

## Returns article with a co-author with id 562360 instead of 562365!
fs_add_authors(id, 562365)
fs_details(id)   

# Or in this case, fails to add coauthor at all
fs_add_authors(id,579438)

# users with profiles work fine
fs_add_authors(id, "Carl Boettiger")

The examples that fail above do so in the same way whether we use names or ids. (Names just query fs_author_search first to get IDs, which we can confirm works and returns ids for the authors above.)

[cboettig]

I filed a bug report with figshare; their dev team is now looking into a fix.