Customize connection timeout

[diegoparrilla]

Hi there,

I'm trying to use the library to perform massive queries to DNS servers, so customizing the timeout is critical. I had to modify the code and change the TIMEOUT constant in resolver.py, but I was wondering if there is a better way to do it. If not, does it make sense to modify the lookup method to allow an optional timeout parameter? Would you accept a PR with this change?

[al45tair]

I think it would either need to be added to the lookup method as an optional argument, or alternatively as a class method on the various Resolver objects. Yes, in principle I'd accept a PR; obviously I'd look through it before merging, and I have been known to write my own changes in response to someone's PR too, so…