Week 5 will become Week 6.
Week 4 will just go over VMs, Vagrant, and deploying to Heroku with git. Homework will be going through the Try Git tutorial on Code School, which has them set up a Github account (awesome). Other homework could be making their website more spiffy and pushing their changes to Heroku and Github.
Week 5 will be an introduction to Sinatra, starting with an exploration of app.rb, a description of /, figuring out routing, and adding a layout to their project. Homework will be installing Ruby with RVM and going through a Sinatra tutorial and going through a basic SQL tutorial.