testes: remove TestDockerDriver_Kill
testes: remove TestDockerDriver_Kill

We already have two other Kill tests (e.g.
TestDockerDriver_Start_Kill_Wait and
TestDockerDriver_Start_KillTimeout), so don't need yet another flaky
test.

dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad,burdandrei/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,burdandrei/nomad