subprocess.Popen takes a PIPE for stdin

http://docs.python.org/2/library/subprocess.html#subprocess.Popen.communicate

   Note that if you want to send data to the process’s stdin, you need to
   create the Popen object with stdin=PIPE.
Merge pull request #7026 from ajithhub/stdin_pipe

subprocess.Popen takes a PIPE for stdin
Merge pull request #7036 from UtahDave/develop

Old ssh clients require -t for ssh-keyscan
Add spaces around assignment operator