fix: Simulation is not deterministic due to GenSignedMockTx (cosmos#1…

…2374)

test_helpers.go

@@ -3,7 +3,9 @@ package simapp
 import (
 	"context"
 	"encoding/json"
+	"math/rand"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 	abci "github.com/tendermint/tendermint/abci/types"
@@ -257,6 +259,7 @@ func SignCheckDeliver(
 	chainID string, accNums, accSeqs []uint64, expSimPass, expPass bool, priv ...cryptotypes.PrivKey,
 ) (sdk.GasInfo, *sdk.Result, error) {
 	tx, err := simtestutil.GenSignedMockTx(
+		rand.New(rand.NewSource(time.Now().UnixNano())),
 		txCfg,
 		msgs,
 		sdk.Coins{sdk.NewInt64Coin(sdk.DefaultBondDenom, 0)},
@@ -307,6 +310,7 @@ func GenSequenceOfTxs(txGen client.TxConfig, msgs []sdk.Msg, accNums []uint64, i
 	var err error
 	for i := 0; i < numToGenerate; i++ {
 		txs[i], err = simtestutil.GenSignedMockTx(
+			rand.New(rand.NewSource(time.Now().UnixNano())),
 			txGen,
 			msgs,
 			sdk.Coins{sdk.NewInt64Coin(sdk.DefaultBondDenom, 0)},