1) Modified build.gradle to add MongoDB Java driver; 2) Modified
AppConfig.groovy to add Bean defintions for MongoDBFactory and
MongoTemplate; 3) Created User.groovy entity and its test class
Removed the DateTimeUtil.groovy class and its test (It has been moved to
a different repo)
Added RabbitMQ. The tests need a little more tweaking, but the code is
completely functioning! To see this in action, you will need to set up
RabbitMQ on your local machine first.