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

node/node_test.go

@@ -16,8 +16,8 @@ import (
 	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/crypto/ed25519"
 	"github.com/tendermint/tendermint/evidence"
-	cmn "github.com/tendermint/tendermint/libs/common"
 	"github.com/tendermint/tendermint/libs/log"
+	"github.com/tendermint/tendermint/libs/rand"
 	mempl "github.com/tendermint/tendermint/mempool"
 	"github.com/tendermint/tendermint/p2p"
 	p2pmock "github.com/tendermint/tendermint/p2p/mock"
@@ -174,7 +174,7 @@ func TestPrivValidatorListenAddrNoProtocol(t *testing.T) {
 }
 
 func TestNodeSetPrivValIPC(t *testing.T) {
-	tmpfile := "/tmp/kms." + cmn.RandStr(6) + ".sock"
+	tmpfile := "/tmp/kms." + rand.RandStr(6) + ".sock"
 	defer os.Remove(tmpfile) // clean up
 
 	config := cfg.ResetTestRoot("node_priv_val_tcp_test")
@@ -257,7 +257,7 @@ func TestCreateProposalBlock(t *testing.T) {
 	minEvSize := 12
 	numEv := (maxBytes / types.MaxEvidenceBytesDenominator) / minEvSize
 	for i := 0; i < numEv; i++ {
-		ev := types.NewMockRandomGoodEvidence(1, proposerAddr, cmn.RandBytes(minEvSize))
+		ev := types.NewMockRandomGoodEvidence(1, proposerAddr, rand.RandBytes(minEvSize))
 		err := evidencePool.AddEvidence(ev)
 		assert.NoError(t, err)
 	}
@@ -266,7 +266,7 @@ func TestCreateProposalBlock(t *testing.T) {
 	// than can fit in a block
 	txLength := 1000
 	for i := 0; i < maxBytes/txLength; i++ {
-		tx := cmn.RandBytes(txLength)
+		tx := rand.RandBytes(txLength)
 		err := mempool.CheckTx(tx, nil, mempl.TxInfo{})
 		assert.NoError(t, err)
 	}