Add Beego ORM in the benchmark suite

After shopping a bit around I saw that Beego.ORM seems to be one of the most efficient Go ORM (don't take my word for that, I'm a new gopher)

Anyway it might be a good idea to add benchmarks for Beego here.
It doesnt do too bad considering that it's quite a neat/complete ORM, I guess we would need to tests different type operations to compare them realistically.