Skeleton example and new exercises
Add some explanation to the example. Fix typos
added script for reading a gzip file
added solution to first if..elif..else exercise
added simple if..elif..else exercise
added the first part of the reading gzip file exercises as an example
removed output
removed output
Update exerice solutions
Merge branch 'master' of https://github.com/pycam/python-intro
minor changes, added an exercise to the 'if' section
Merge branch 'master' into release
updating release branch with executed code