fix(frost-secp256k1-tr): add missing pub mod refresh and missing test (#806)

Author: StackOverflowExcept1on

frost-secp256k1-tr/src/lib.rs

@@ -787,6 +787,7 @@ pub mod keys {
     }
 
     pub mod dkg;
+    pub mod refresh;
     pub mod repairable;
 }
 

frost-secp256k1-tr/tests/integration_tests.rs

@@ -181,6 +181,13 @@ fn check_refresh_shares_with_dealer_fails_with_invalid_identifier() {
     >(max_signers, min_signers, &identifiers, error, rng);
 }
 
+#[test]
+fn check_refresh_shares_with_dkg() {
+    let rng = thread_rng();
+
+    frost_core::tests::refresh::check_refresh_shares_with_dkg::<Secp256K1Sha256TR, _>(rng);
+}
+
 #[test]
 fn check_sign_with_dealer() {
     let rng = thread_rng();