idempotent KojiBuilder implementation of rida/builder.py
* allows to call build() and connect() multiple times
This needs to be followed by allowing resubmiting module build tasks in REST
* rename buildroot_add_repo to buildroot_add_repos() (input data is artifactS)
* Nils is disappointed by Guido
Signed-off-by: Lubos Kocman <lkocman@redhat.com>