Validates if the given input is a punct.
Valid values:
validator.punct().validate('.');
validator.punct().validate(',;:');
validator.punct().validate('-@#$*');
validator.punct().validate('!%^&');
validator.punct().validate('()[]{}');Invalid values:
validator.punct().validate('');
validator.punct().validate(null);
validator.punct().validate(undefined);
validator.punct().validate('16-50');
validator.punct().validate('a');
validator.punct().validate(' ');
validator.punct().validate('Foo');
validator.punct().validate('12.1');
validator.punct().validate('-12');
validator.punct().validate(-12);
validator.punct().validate('( )_{}');