Fix clippy lints

beacon_chain/utils/bls/src/aggregate_signature.rs

@@ -6,7 +6,7 @@ use bls_aggregates::AggregateSignature as RawAggregateSignature;
 ///
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
-#[derive(Debug, PartialEq, Clone)]
+#[derive(Debug, PartialEq, Clone, Default)]
 pub struct AggregateSignature(RawAggregateSignature);
 
 impl AggregateSignature {

beacon_chain/utils/slot_clock/src/system_time_slot_clock.rs

@@ -26,7 +26,7 @@ impl SystemTimeSlotClock {
         if slot_duration_seconds == 0 {
             Err(Error::SlotDurationIsZero)
         } else {
-            Ok(SystemTimeSlotClock {
+            Ok(Self {
                 genesis_seconds,
                 slot_duration_seconds,
             })