Fixed small quote escaping issues. 

Was reviewing http://notes.code61.org/c1s3/#!3_bootstrap_layout before tomorrow's class and HTML for one of the exercises has gotten overly escaped at some point. 

![image](https://cloud.githubusercontent.com/assets/1028109/4968688/4243b376-6848-11e4-9273-dd1f996aebac.png)