Created ack.py module and first draft ack() function
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Added detail to docstring and table of expected values for assert
Fixed indentation
ack.py tested and finalized
Created series.py with draft of fibonacci()
Split fibonacci() into helper functions to avoid checking values at each recursion
Added first draft of lucas()
Added values to check lucas(n)
Add first draft of series_sum()
Renamed series_sum() to sum_series(); added assert checks for sum_series()
Created ack.py, an implementation of the Ackermann function.
Add comments to err checking and improved docstrings
Add comments and edit docstring of ack.py
Switched to a loop to run the tests of the Ackermann function
Merge pull request #33 from brentnunn/master

Created ack.py, an implementation of the Ackermann function.
Merge remote-tracking branch 'upstream/master'
Replace print 'err str' with raise ValueError('str') for clairty of err msg
Edit to return None on negative values to match specification