Refactored Parser#run to be idiomatic ruby
Used the extract method pattern to pull out 2 new helper methods

2 new tests in parser to test the methods I extracted. The tests
        were written against the original code before I made the
        refactor.

* removal of _ prefix on local variables
* #run is now shorter and more expressive
* opt for reduce over each instead of declaring a local collection
        and then 'stuffing' it on each iteration
* opt for an inline hash and declarations