Required files
specinfra/backend/base
specinfra/backend/exec
specinfra/backend/ssh
specinfra/backend/powershell/script_helper
specinfra/backend/powershell/command
specinfra/backend/cmd
specinfra/backend/docker
specinfra/backend/lxc
specinfra/backend/winrm
specinfra/backend/shell_script
specinfra/backend/dockerfile
specinfra/backend/telnet
specinfra/backend/jexec