GPII-434: General cleanup and rationalisation for Kettle 

all test infrastructure definitions placed in namespace "kettle.test" with actual tests in "kettle.tests" - test infrastructure now loads automatically with the module - grunt tasks for linting, together with all files linted revealed various implementation problems with tests. Added gpii-grunt as a dev dependency in order to get access to "dedupe-infusion" task. Clear distinction made between "tests in the Kettle environment" and "tests based around a Kettle server" - former are bootstrapped with kettle.test.bootstrap, and latter with kettle.test.bootstrapServer
I think it's worth trying to describe this a little bit more clearly if possible. I had to read this description twice to parse that apps were things that are grouped together into servers. Are there any other characteristics of apps we can describe to make them more tangible?