Added connect timeout.
Added connect timeout.

In some networks, the net client could a very long time to return with an error in case the host does not exist.

jorgebay/node-cassandra-cql,connor4312/nodejs-driver,datastax/nodejs-driver,datastax/nodejs-driver,layerhq/nodejs-driver,Teino1978-Corp/nodejs-driver,jorgebay/nodejs-driver,jonathanleang/nodejs-driver,ably-forks/nodejs-driver,thiagoveras/nodejs-driver,Applifier/node-cassandra-cql,chrisjsimpson/nodejs-driver,Applifier/nodejs-driver