Add DepositParametersRecord to protobuf types (prysmaticlabs#1042)

* Add DepositParametersRecord

* _hash32

proto/beacon/p2p/v1/types.proto

@@ -1,4 +1,3 @@
-
 syntax = "proto3";
 
 package ethereum.beacon.p2p.v1;
@@ -94,7 +93,7 @@ message AttestationData {
 message ValidatorRecord {
   bytes pubkey = 1;
   // TODO(781): The usage of withdrawal_credentials is not defined in spec. Not used in Prysm yet.
-  bytes withdrawal_credentials = 2;
+  bytes withdrawal_credentials = 2; // TODO(781): this is hash32, rename with suffix _hash32
   bytes randao_commitment_hash32 = 3;
   uint64 randao_skips = 4;
   // Balance in Gwei
@@ -178,3 +177,11 @@ message BeaconBlock {
   // All fields must be annotated with [deprecated=true];
   google.protobuf.Timestamp timestamp = 1006 [deprecated=true]; // Keeping this until we refactor block validation.
 }
+
+message DepositParametersRecord {
+  bytes pubkey = 1;
+  bytes proof_of_possession = 2; // Type of ['uint384']??
+  // TODO(781): The usage of withdrawal_credentials is not defined in spec. Not used in Prysm yet.
+  bytes withdrawal_credentials_hash32 = 3;
+  bytes randao_commitment_hash32 = 4;
+}