Attempt "none" authentication which usually will (and should) fail.
As part of the failure, this function will return an array of accepted
authentication methods.
Parameters
session
An SSH connection link identifier, obtained from a call to
ssh2_connect().
username
Remote user name.
Return Values
Returns TRUE if the server doesc accept "none" as an authentication
method, or an array of accepted authentication methods on failure.
Examples
Example #1 Retreiving a list of authentication methods
Load balance : Server 01
