rust-bindgen from home:kentaurest project

For 16.0 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/home:kentaurest/16.0/home:kentaurest.repo
zypper refresh
zypper install rust-bindgen

For 15.6 run the following as root:

zypper addrepo https://download.opensuse.org/repositories/home:kentaurest/15.6/home:kentaurest.repo
zypper refresh
zypper install rust-bindgen