Set up and use New Relic

https://trello.com/c/WKSxzMlK/234-set-up-new-relic
Remove link to thoughtbot's style guide on homepage

Having a link to thoughtbot's style guide obscures that hound is
configurable.

https://github.com/thoughtbot/hound/issues/203
https://trello.com/c/wYwsF46g
Test method chaining
Enable IndentationConsistency rule
Remove remaining pending tests