clean up
clean up
clean up
clean up
clean up
various updates and new answer books
update start scripts
remove checkpoint
Clean-up of chapter 2

Copy-editing of chapter 2.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Chapter 2 - First steps.ipynb
Resolved conflicts in chapter 2
Merge pull request #5 from sonofmun/master

Copy-edited Chapter 2