Incorrect values for modInverse function

[HoangNguyen219]

Describe the bug
Incorrect values for modInverse function

To Reproduce
Steps to reproduce the behavior:

    @Test
    fun testModInverse() {
        val a = BigInteger.parseString("54647")
            .modInverse(BigInteger.parseString("1157920"))

        assertEquals(
            BigInteger.parseString("1141223"),
            a
        )

Expected :1141223
Actual   :-16697

Expected behavior
In java.math this test is successful:

    @Test
    public void testModInverse() {
        BigInteger a = new BigInteger("54647")
                .modInverse(new BigInteger("1157920"));
        assertEquals(new BigInteger("1141223"), a);
    }

[ionspin]

Thanks for reporting, I'll give it a look when I have some free time.

[ionspin]

Fixed in #306