Update deprecations.

test/hmac_sha1_test.dart

Index: test/hmac_sha1_test.dart
diff --git a/test/hmac_sha1_test.dart b/test/hmac_sha1_test.dart
index 9f4a5103bf22be6d2a89fcad335504c91fb759fd..c7fc66ddce433277dceccbcdbb355b8f3c308f73 100644
--- a/test/hmac_sha1_test.dart
+++ b/test/hmac_sha1_test.dart
@@ -12,7 +12,7 @@ void main() {
   group("standard vector", () {
     for (var i = 0; i < _inputs.length; i++) {
       test(_macs[i], () {
-        expectHmacEquals(new SHA1(), _inputs[i], _keys[i], _macs[i]);
+        expectHmacEquals(sha1, _inputs[i], _keys[i], _macs[i]);
       });
     }
   });