Add lecture 15
Make some descriptions prettier
Add more slides
Test commit
Remove unneeded blank lines
Add intro slides related to education
Mention that we'll release a 3rd assignment today
Add info slides about the course projects
Add some bonus slides, in case we have the time
Merge other slides
Add GitHub for Windows, GitX and TortoiseGit screenshots
Add motivational slide
Remove unseen slides for Hash#to_proc
Add the git lecture (15)
Merge pull request #66 from stormbreakerbg/15-git-lecture

Add the git lecture (number 15)
Add lecture 16 - web and Sinatra
Fix a typo in lecture 16
Merge branch 'git-lecture'

Conflicts:
	lectures/index.yml
Explain about the four file areas first
Reword the explanations for the 4 file states

This makes it a bit more formal, but I believe it should be easier
to understand in the context of the previous slides.