Check if the resume path points to a directory (#7919)
Check if the resume path points to a directory (#7919)

This came up in #7878, but if --resume-path is a directory then loading
the weights will fail. On Linux this will give a straightforward error
message, but on Windows it gives "Permission Denied", which is
confusing.
honnibal/spaCy,explosion/spaCy,honnibal/spaCy,explosion/spaCy,honnibal/spaCy,explosion/spaCy,explosion/spaCy,explosion/spaCy,honnibal/spaCy,explosion/spaCy