Add sqlite support

[kifirkin]

I think sqlite easier and more faster way for development purposes.

It's very easy to add sqlite3 support with import gorm/dialects/sqlite inside db/db.go
and new adapter config

if config.Config.DB.Adapter == "sqlite" {
	DB, err = gorm.Open("sqlite3", fmt.Sprintf("%v\\%v.sqlite3", os.TempDir(), dbConfig.Name))
}

But it depends on mattn/go-sqlite3 wich needs gcc available on path.

I've got msys2 with mingw-w64-x86_64-toolchain on my Windows 7 machine and it works perfect for me.