added files for testing lesson
Removed 'next steps'
commented NaN lines in test
fixes after reviewe for 04-cond.md
Minor fixes to 03-func and 04-cond
Merge branch 'master' of https://github.com/swcarpentry/bc into matlab-05-defensive

Conflicts:
	novice/matlab/02-loop.md
	novice/matlab/03-func.md
	novice/matlab/04-cond.md
fixed duplicate output
small fixes to lesson 5
Merge pull request #799 from ashwinsrnth/matlab-05-defensive

Matlab lesson on defensive programming