Merge pull request #149 from williamscott/master

Minor editing changes on Chapter 2
Merge pull request #151 from williamscott/master

Minor editing changes to chapters 2 and 3
Merge pull request #152 from williamscott/here

Delete superfluous row in table
Merge pull request #153 from williamscott/master

Typos and phrasing changes
fix recent typos causing invalid JSON

recent commit (dfc565c1561bb05b71a316d2073efeb7c6f50e66) edited Chapter 1,
introducing typos and making it invalid JSON. This fixes those typos.
Merge pull request #154 from minrk/lambdas

fix recent typos causing invalid JSON
Merge remote-tracking branch 'upstream/master'