In the main method, use the libssh API to create a new ssh_session. Ensure that the session is successfully created.
Connect to the localhost. 
Authenticate the server (check that it is in the known host file) and authenticate the user to the server.
Disconnect from the server and free the session.
Create and open a new ssh_channel in the ssh_session. 
Execute the command "who" on the open channel.
Read in response from the channel and print it to stdout.
Shut down the channel by sending the eof and closing and freeing the channel.
Create and initialize a new sftp_session on the connected ssh_session.
Create a new directory "Dir1". Return any errors, but do not return if the directory already exists.
Create a new file in Dir1 called "File1".
Write the string "Hello, world!" to the file.
Close the file, and free the sftp session.