In current setup, we rely on executor to perform render operation,
however there are many usecases, when we want to have a simple
`kustomize build` performed against document entrypoint in phase.
Now this will be a default behaviour and if a user would like
executor to perform rendering to actually understand what it's
doing, he will be able to specify --executor boolean flag.
Relates-To: #403
Change-Id: I181830f9814ff48a19ba0a1284e89900187bc7d8