Monitor all git commands; move blame to git package and replace git as a variable (#6864)

* monitor all git commands; move blame to git package and replace git as a variable

* use git command but not other commands

* fix build

* move exec.Command to git.NewCommand

* fix fmt

* remove unrelated changes

* remove unrelated changes

* refactor IsEmpty and add tests

* fix tests

* fix tests

* fix tests

* fix tests

* remove gitLogger

* fix fmt

* fix isEmpty

* fix lint

* fix tests

models/update.go

@@ -7,7 +7,6 @@ package models
 import (
 	"container/list"
 	"fmt"
-	"os/exec"
 	"strings"
 	"time"
 
@@ -193,9 +192,8 @@ func pushUpdate(opts PushUpdateOptions) (repo *Repository, err error) {
 
 	repoPath := RepoPath(opts.RepoUserName, opts.RepoName)
 
-	gitUpdate := exec.Command("git", "update-server-info")
-	gitUpdate.Dir = repoPath
-	if err = gitUpdate.Run(); err != nil {
+	_, err = git.NewCommand("update-server-info").RunInDir(repoPath)
+	if err != nil {
 		return nil, fmt.Errorf("Failed to call 'git update-server-info': %v", err)
 	}