Feature request: Multi-threaded mock ftp server (in conn_test.go)

[dhait]

A few users (e.g. #206 and #128 ) have asked for a feature and/or guidance on how to create a connection pool for FTP access, which is a critical use case for FTP servers that limit simultaneous access by a single user. It would be much easier to implement this and test it if the mock ftp server include in conn_test.go were able to support multiple simultaneous connections.

I have done some work in this area and would be happy to submit a PR if you are amenable.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.