Fix deprecated method and test failure

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "curv-kzen"
-version = "0.10.0"
+version = "0.10.1"
 edition = "2018"
 authors = [
     "Omer Shlomovits",

src/arithmetic/big_native.rs

@@ -246,7 +246,8 @@ impl Integer for BigInt {
     }
 
     fn divides(&self, other: &Self) -> bool {
-        self.num.divides(&other.num)
+        // num_bigint::bigint::divides is depricated
+        self.num.is_multiple_of(&other.num)
     }
 
     fn is_multiple_of(&self, other: &Self) -> bool {

src/arithmetic/big_native/primes.rs

@@ -503,7 +503,7 @@ fn is_bit_set(x: &BigUint, i: usize) -> bool {
 fn gen_biguint_below<R: Rng>(r: &mut R, upper: &BigUint) -> BigUint {
     loop {
         let bits = upper.bits();
-        let bytes = bits.div_ceil(&8);
+        let bytes = bits.div_ceil(8);
         let mut buf = vec![0u8; bytes as usize];
         r.fill_bytes(&mut buf);