Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Update README.md
Updates to Appendix A. Refs #62
Adding more Python idioms and ipynb tips in App C
Adding missing file for ch07
Minor updates to appendices
Minor update to App A
Adding new YouTube video that illustrates Appendix A
Tweaking instructions for install
Update README.md
Update README.md
Adding sample data to faciliate learning in ch06

Adding a ~30MB data file to simplify the process of getting data that
can be loaded into MongoDB, a process that can be quite time-consuming
because of all of the time that it takes Vagrant to synchronize the
thousands of files back to the host system that unarchive from the
original download.
Adding centrality analysis to ch07 ipynb
Workaround for ipynb viewer nested lists bug