Instead of using assertions to make sure a Circle object isn't instantiated with a zero or negative radius or diameter, used and if statement with a raise ValueError.
Updated test module for circle.py to test that the ValueError is raised in the case of an attempted instantiation of a Circle object with a negative or zero radius (or diameter), instead of the AssertionError.
Merge branch 'master' of https://github.com/UWPCE-PythonCert/IntroToPython
separated sparse array from sparse array using slices, have all tests passing, probably need more tests
merged stuff, good catch Chis. got rid of bad print statement
Merge pull request #83 from imdavis/master

Session 07 Assignment: Circle Class
final session 9 presentation
Merge branch 'master' of https://github.com/UWPCE-PythonCert/IntroToPython
Merge branch 'session08' of https://github.com/UWPCE-PythonCert/IntroToPython into session08
Merge branch 'session08'
Merge branch 'master' of https://github.com/UWPCE-PythonCert/IntroToPython