In some cases, (e.g. private key not accessible or has incorrect
permissions) docker-machine failed with error "Something went wrong
running an SSH command!". This commit will add the correct debug
messages and show the correct errors for the bad private keys.
Also, due to incorrect handling POSIX file permissions in Windows
some checks should be ignored.
Signed-off-by: Maksim Malchuk <maksim.malchuk@gmail.com>
be8f469a82