sshj has intermittent errors doing sftp to Tectia servers

[ahgittin]

When brooklyn (using sshj) tries to copy the script to the target machine, we sometimes encounter:

ERROR net.schmizz.concurrent.Promise - <<sftp / 4>> woke to: net.schmizz.sshj.sftp.SFTPException: EOF while reading packet
Exception in thread "main" net.schmizz.sshj.sftp.SFTPException: EOF while reading packet

The target machine is running Tectia ssh server, so I suspect we are running in to hierynomus/sshj#54 .

Options to resolve:

• investigate fixing the problem in sshj
• add ability for Brooklyn to use CLI ssh as an alternative to sshj

[grkvlt]

Have installed Tectia on an RHEL machine on AWS to reproduce issue and investigating what the underlying sshj issue is