Add attestation gossip pre-verification (#983)

* Add PH & MS slot clock changes

* Account for genesis time

* Add progress on duties refactor

* Add simple is_aggregator bool to val subscription

* Start work on attestation_verification.rs

* Add progress on ObservedAttestations

* Progress with ObservedAttestations

* Fix tests

* Add observed attestations to the beacon chain

* Add attestation observation to processing code

* Add progress on attestation verification

* Add first draft of ObservedAttesters

* Add more tests

* Add observed attesters to beacon chain

* Add observers to attestation processing

* Add more attestation verification

* Create ObservedAggregators map

* Remove commented-out code

* Add observed aggregators into chain

* Add progress

* Finish adding features to attestation verification

* Ensure beacon chain compiles

* Link attn verification into chain

* Integrate new attn verification in chain

* Remove old attestation processing code

* Start trying to fix beacon_chain tests

* Split adding into pools into two functions

* Add aggregation to harness

* Get test harness working again

* Adjust the number of aggregators for test harness

* Fix edge-case in harness

* Integrate new attn processing in network

* Fix compile bug in validator_client

* Update validator API endpoints

* Fix aggreagation in test harness

* Fix enum thing

* Fix attestation observation bug:

* Patch failing API tests

* Start adding comments to attestation verification

* Remove unused attestation field

* Unify "is block known" logic

* Update comments

* Supress fork choice errors for network processing

* Add todos

* Tidy

* Add gossip attn tests

* Disallow test harness to produce old attns

* Comment out in-progress tests

* Partially address pruning tests

* Fix failing store test

* Add aggregate tests

* Add comments about which spec conditions we check

* Dont re-aggregate

* Split apart test harness attn production

* Fix compile error in network

* Make progress on commented-out test

* Fix skipping attestation test

* Add fork choice verification tests

* Tidy attn tests, remove dead code

* Remove some accidentally added code

* Fix clippy lint

* Rename test file

* Add block tests, add cheap block proposer check

* Rename block testing file

* Add observed_block_producers

* Tidy

* Switch around block signature verification

* Finish block testing

* Remove gossip from signature tests

* First pass of self review

* Fix deviation in spec

* Update test spec tags

* Start moving over to hashset

* Finish moving observed attesters to hashmap

* Move aggregation pool over to hashmap

* Make fc attn borrow again

* Fix rest_api compile error

* Fix missing comments

* Fix monster test

* Uncomment increasing slots test

* Address remaining comments

* Remove unsafe, use cfg test

* Remove cfg test flag

* Fix dodgy comment

* Ignore aggregates that are already known.

* Unify aggregator modulo logic

* Fix typo in logs

* Refactor validator subscription logic

* Avoid reproducing selection proof

* Skip HTTP call if no subscriptions

* Rename DutyAndState -> DutyAndProof

* Tidy logs

* Print root as dbg

* Fix compile errors in tests

* Fix compile error in test

beacon_node/rest_api/tests/test.rs

@@ -93,11 +93,20 @@ fn validator_produce_attestation() {
     let genesis_validators_root = beacon_chain.genesis_validators_root;
     let state = beacon_chain.head().expect("should get head").beacon_state;
 
-    let validator_index = 0;
-    let duties = state
-        .get_attestation_duties(validator_index, RelativeEpoch::Current)
-        .expect("should have attestation duties cache")
-        .expect("should have attestation duties");
+    // Find a validator that has duties in the current slot of the chain.
+    let mut validator_index = 0;
+    let duties = loop {
+        let duties = state
+            .get_attestation_duties(validator_index, RelativeEpoch::Current)
+            .expect("should have attestation duties cache")
+            .expect("should have attestation duties");
+
+        if duties.slot == node.client.beacon_chain().unwrap().slot().unwrap() {
+            break duties;
+        } else {
+            validator_index += 1
+        }
+    };
 
     let mut attestation = env
         .runtime()
@@ -134,15 +143,18 @@ fn validator_produce_attestation() {
 
     // Try publishing the attestation without a signature or a committee bit set, ensure it is
     // raises an error.
-    let publish_result = env.runtime().block_on(
-        remote_node
-            .http
-            .validator()
-            .publish_attestations(vec![attestation.clone()]),
-    );
+    let publish_status = env
+        .runtime()
+        .block_on(
+            remote_node
+                .http
+                .validator()
+                .publish_attestations(vec![attestation.clone()]),
+        )
+        .expect("should publish unsigned attestation");
     assert!(
-        publish_result.is_err(),
-        "the unsigned published attestation should return error"
+        !publish_status.is_valid(),
+        "the unsigned published attestation should be invalid"
     );
 
     // Set the aggregation bit.
@@ -224,6 +236,7 @@ fn validator_produce_attestation() {
     let signed_aggregate_and_proof = SignedAggregateAndProof::from_aggregate(
         validator_index as u64,
         aggregated_attestation,
+        None,
         &keypair.sk,
         &state.fork,
         genesis_validators_root,