delete uv_work_t at end of callback

[steve-lawson]

Found a small memory leak.

[mariano]

Nice catch! Wouldn't it be better to delete the request from Execute itself instead of ExecuteFinished. Since request was created here, it probably makes more sense to delete it here

[steve-lawson]

I think that request needs to stay around until the callback finishes, then it is deleted here, but req created here was not being deleted?