unit testing ratpack handlers
Merge pull request #155 from tomaslin/master

Beginnings of testing chapter
Minor build tweak.
Merge pull request #153 from rhart/master

Javadoc improvements for Chain interface (#147)
Some docs on Chain (#147)
Convert snippet to Java and test it on Chain interface (#147)
Rename path(String, Handler) to handler(String, Handler).
Minor javadoc improvement.
Rename groovy version of handler(String, Closure)