refactor(db): change SQLite driver from github.com/jinzhu/gorm/dialects/sqlite to github.com/glebarez/go-sqlite (#1626)

* sqlite 驱动从 github.com/jinzhu/gorm/dialects/sqlite 改为 github.com/glebarez/go-sqlite，以移除对 cgo 的依赖

* // 兼容已有配置中的 "sqlite3" 配置项

* Update models/init.go: 修改变量名

models/migration_test.go

@@ -10,8 +10,8 @@ import (
 
 func TestMigration(t *testing.T) {
 	asserts := assert.New(t)
-	conf.DatabaseConfig.Type = "sqlite3"
-	DB, _ = gorm.Open("sqlite3", ":memory:")
+	conf.DatabaseConfig.Type = "sqlite"
+	DB, _ = gorm.Open("sqlite", ":memory:")
 
 	asserts.NotPanics(func() {
 		migration()