Configure and install required services

This pull request is a part of the issue : https://github.com/DemandCube/hadoop-single-node-cluster/issues/9

Usage:
-s - Prints all the services
-a "SERVICE1 SERVICE2"  --> forces by default and installs the services mentioned
This is bad practice, because it depends on functions being executed in a specific order.  Can you declare variables with functions that will call them.  You should declare them as local too, other wise make them global as part of the parent script.