For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mkubecek:rc0/openSUSE_Tumbleweed/home:mkubecek:rc0.repo
zypper refresh
zypper install kernel-obs-build
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mkubecek:rc0/16.0/home:mkubecek:rc0.repo
zypper refresh
zypper install kernel-obs-build
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mkubecek:rc0/15.6/home:mkubecek:rc0.repo
zypper refresh
zypper install kernel-obs-build