DC/OS 1.9

Refactoring und made 1.9 compatible. (#4)

* initial refactoring

* killing of basic tasks works

* Updates link for DC/OS CLI installation

* Updates marathon definition file and jobs decription to run rampage during business hours

* fixes bug with cron schedule

* prevents drax from killing himself

* prevents drax from killing frameworks

* adds json result output for /rampage

* enables /stats endpoint

* Updates README

* Adds configurable sleep time between the killing of tasks