fix simulation test, marshal json process

x/gov/simulation/operations.go

@@ -386,7 +386,7 @@ func operationSimulateMsgVoteWeighted(ak types.AccountKeeper, bk types.BankKeepe
 			return simtypes.NoOpMsg(types.ModuleName, msg.Type(), "unable to deliver tx"), nil, err
 		}
 
-		return simtypes.NewOperationMsg(msg, true, ""), nil, nil
+		return simtypes.NewOperationMsg(msg, true, "", nil), nil, nil
 	}
 }
 

x/gov/types/vote.go

@@ -1,13 +1,12 @@
 package types
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 
-	yaml "gopkg.in/yaml.v2"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	proto "github.com/gogo/protobuf/proto"
+	yaml "gopkg.in/yaml.v2"
 )
 
 // NewVote creates a new Vote instance
@@ -62,7 +61,7 @@ func NewNonSplitVoteOption(option VoteOption) WeightedVoteOptions {
 }
 
 func (v WeightedVoteOption) String() string {
-	out, _ := proto.Marshal(&v)
+	out, _ := json.Marshal(v)
 	return string(out)
 }