Use pasta_curves 0.3.0. (#15)

Co-authored-by: porcuquine <porcuquine@users.noreply.github.com>

Cargo.toml

@@ -21,4 +21,4 @@ rayon = "1.3.0"
 rand_core = { version = "0.5", default-features = false }
 itertools = "0.9.0"
 subtle = "2.4"
-pasta_curves = "0.2.1"
+pasta_curves = "0.3.0"

src/pasta.rs

@@ -62,8 +62,8 @@ impl PrimeField for pallas::Scalar {
     }
   }
 
-  fn random(_rng: &mut (impl RngCore + CryptoRng)) -> Self {
-    Fq::rand()
+  fn random(rng: &mut (impl RngCore + CryptoRng)) -> Self {
+    <Fq as ff::Field>::random(rng)
   }
 }