urlSafeB64Encode function mistake

[nasaorc]

in file Jwt.php

$b64 = str_replace(array('+', '/', '\r', '\n', '='),
                array('-', '_'),
                $b64);

the '\r' and '\n' won't match new lines

single quotation mark will match \n as string(2) '\n'

to match new line should use "\n" instead

[bshaffer]

Thank you for catching this!