Update consume_test.js

multiple options object creates confusion. Removed one.
Update produce_test.js

currently the producer was throwing "error undefined" with each message sent to kafka. code was edited to log errors only if error is defined.
fixed issue while trying reset the read offset to 0.

If we are passing offset 0 with options passed to consumer, the offset never gets reset to 0 but instead sets to last offset due to the if(options.offset) check done. So the condition was edited accordingly.
Merge pull request #37 from mithunsatheesh/master

Updates on consume_test, produce_test, and Consumer.js