Refactors codebase

Refactors duplicated code. Renames and reorganizes classes and methods.
Refactors tests.
Kafka message handling is removed from plugins. They now return response msg
dict and top level code handles publishing.

Signed-off-by: Benjamin Diaz <bdiaz@whitestack.com>
Change-Id: I9826db9c4586d961f40af6cb194fc388fe855ae1
35 files changed