Create Authentication.java

/** Program that simulates the authentication process and requires
 *  a 5 digit pin entry. The system guards against "shoulder surfing" attacks, 
 *  where a thief looks over a victim's shoulder while they are entering their
 *  pin number. The system uses a randomized challenge-response where digits 
 *  are entered based on a code displayed to the screen. The code changes at
 *  each login. An array is used to assign random numbers between 0 and 9 and 
 *  then output to the screen. The user enters the random numbers that 
 *  corresponds to their pin. If a match is found the login is successful.
 */