Card validation method does not work properly

[petrnohejl]

Method Card.isValid() does not work:

• If I set expiration month to 13, it returns true
• If I set expiration year to some past value, e.g. 2012, it returns true

[petrnohejl]

Method Card.isExpired() seems to be wrong.

This code makes no sense:

if (expirationMonth > 12 || expirationYear < 1) { return false; }

Probably should be:

if(expirationMonth > 12 || expirationMonth < 1) return true; // true means invalid/expired

Btw, second line in following code is useless, because Calendar.getInstance() returns current date.

Calendar cal = Calendar.getInstance();
cal.setTime(new Date()); // this is useless

[remear]

@petrnohejl Yes. it should return true. Would you like to open a pull request to make these changes?