This is an assigned coding challenge.

This app collects all of the words in a text file (which the user provides), removes any stop words found
in another file (which the user also provides), removes all non-alphabetical text, stems all remaining
words into their root form, computes the frequency of each term, and prints out the 20 most commonly
occurring terms in descending order of frequency.

To run:
    1) cd to the 'text-analyzer' (project root) folder.
    2) python run_text_analyzer.py