libs/common: refactor libs/common 2 (#4231)

* libs/common: refactor libs/common 2

- move random function to there own pkg

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* change imports and usage throughout repo

* fix goimports

* add changelog entry

cmd/tendermint/commands/init.go

@@ -6,6 +6,7 @@ import (
 	"github.com/spf13/cobra"
 	cfg "github.com/tendermint/tendermint/config"
 	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/libs/rand"
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/privval"
 	"github.com/tendermint/tendermint/types"
@@ -55,7 +56,7 @@ func initFilesWithConfig(config *cfg.Config) error {
 		logger.Info("Found genesis file", "path", genFile)
 	} else {
 		genDoc := types.GenesisDoc{
-			ChainID:         fmt.Sprintf("test-chain-%v", cmn.RandStr(6)),
+			ChainID:         fmt.Sprintf("test-chain-%v", rand.RandStr(6)),
 			GenesisTime:     tmtime.Now(),
 			ConsensusParams: types.DefaultConsensusParams(),
 		}

cmd/tendermint/commands/testnet.go

@@ -12,6 +12,7 @@ import (
 
 	cfg "github.com/tendermint/tendermint/config"
 	cmn "github.com/tendermint/tendermint/libs/common"
+	"github.com/tendermint/tendermint/libs/rand"
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/privval"
 	"github.com/tendermint/tendermint/types"
@@ -167,7 +168,7 @@ func testnetFiles(cmd *cobra.Command, args []string) error {
 
 	// Generate genesis doc from generated validators
 	genDoc := &types.GenesisDoc{
-		ChainID:         "chain-" + cmn.RandStr(6),
+		ChainID:         "chain-" + rand.RandStr(6),
 		ConsensusParams: types.DefaultConsensusParams(),
 		GenesisTime:     tmtime.Now(),
 		Validators:      genVals,
@@ -261,5 +262,5 @@ func moniker(i int) string {
 }
 
 func randomMoniker() string {
-	return cmn.HexBytes(cmn.RandBytes(8)).String()
+	return cmn.HexBytes(rand.RandBytes(8)).String()
 }