Update gitignore file
For automated tests, put zookeeper host in config file

Alter Makefile to make it run tests on a Windows machine
Change way options are sent to producer class

Correct bug where when we try to send 2 ProduceRequests with the same topic and partition, the app hangs

Support producer sending messages to multiple partitions randomly or based on a key
Add keyed producer example in example/producer.js file

Add Partitioned Producer test case to verify messages are written to the correct partitions when using a keyed producer