(TK-69) Add new webrouting example using compojure

Add a new webrouting example that adds a ring handler using
compojure that changes depending on the path it is given.
Update webrouting example and webrouting docs to use `this`
instead of `get-service` when using the webrouting service.
Merge pull request #73 from fpringvaldsen/TK-69-new-example

(TK-69) Add new webrouting example using compojure