For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:matwey:branches:devel:languages:erlang/openSUSE_Factory/home:matwey:branches:devel:languages:erlang.repo
zypper refresh
zypper install erlang-rebar-testsuite
For bleeding edge erlang Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:matwey:branches:devel:languages:erlang/bleeding_edge_erlang_Factory/home:matwey:branches:devel:languages:erlang.repo
zypper refresh
zypper install erlang-rebar-testsuite