Variable packaging

In the first commit, I removed some unused variables and changed what looked like a typo for a variable from c02400 to c20400. 

In the second commit, I changed the overall structure of the tax calculator, to begin some basic packaging. The previous global variables have been packaged into separate files that can be imported from the main calculate.py file which retains the main functionality of translation.py. The test function previously at the end of translation.py has been separated into test.py. Running test.py, will import and use the calculations defined in calculate.py, which imports variables from pufVariables.py and constantVariables.py