[WIP] Add option to cancel a build

this is a rough draft, I'm actively working on it.. so it may throw errors and it may have dirty code.

   - Add cancelling and cancelled status for builds
   - Remove pod and update builds to cancelled when a cancel event was triggered for the build
this seems confusing to me, so the final command is then:

`openshift kube cancel 1234` ?

I would prefer `openshift kube cancelBuild <id>` and in kubectl it would be `openshift kubectl cancel-build <id>`