[NOD-294] Fix golint in deploy.sh and fix all lint warnings (#380)

* [NOD-294] Fix golint in deploy.sh and fixed all lint errors

* [NOD-294] Fix typos in comments

* [NOD-294] Convert VirtualForTest into alias of *virtualBlock

* [NOD-294] Fixed some more typos in comments

cmd/jsonrpcifyer/server.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -48,7 +47,7 @@ func (s *server) start() error {
 
 	rpcClient, err := rpcclient.New(s.rpcConnConfig, nil)
 	if err != nil {
-		return errors.New(fmt.Sprintf("failed to create RPC client: %s", err))
+		return fmt.Errorf("failed to create RPC client: %s", err)
 	}
 	s.rpcClient = rpcClient
 
@@ -103,18 +102,18 @@ func (s *server) forwardRequest(request *http.Request) ([]byte, error) {
 
 	requestBody, err := ioutil.ReadAll(request.Body)
 	if err != nil {
-		return nil, errors.New(fmt.Sprintf("failed to read request body: %s", err))
+		return nil, fmt.Errorf("failed to read request body: %s", err)
 	}
 
 	var jsonRPCParams []json.RawMessage
 	err = json.Unmarshal(requestBody, &jsonRPCParams)
 	if err != nil {
-		return nil, errors.New(fmt.Sprintf("failed to parse params: %s", err))
+		return nil, fmt.Errorf("failed to parse params: %s", err)
 	}
 
 	response, err := s.rpcClient.RawRequest(jsonRPCMethod, jsonRPCParams)
 	if err != nil {
-		return nil, errors.New(fmt.Sprintf("request to rpc server failed: %s", err))
+		return nil, fmt.Errorf("request to rpc server failed: %s", err)
 	}
 
 	return response, nil

cmd/txgen/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+
 	"github.com/daglabs/btcd/btcec"
 	"github.com/daglabs/btcd/dagconfig"
 	"github.com/daglabs/btcd/signal"
@@ -11,7 +12,7 @@ import (
 )
 
 var (
-	activeNetParams  *dagconfig.Params = &dagconfig.DevNetParams
+	activeNetParams  = &dagconfig.DevNetParams
 	p2pkhAddress     util.Address
 	secondaryAddress util.Address
 	privateKey       *btcec.PrivateKey