This is another entry into my Programming For Fun Diary (PFFD)

I am adding a new abstraction called Program. Program is a collection of instructions that can be executed on a machine (more specifically the virtual machine abstraction that I created in one of my previous entries). I will start with a completely empty Program abstraction. I will add more functionality later. 

Here is the PR to add the Program abstraction — https://github.com/adhithyan15/programming-for-fun/pull/4