For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/network:messaging:matrix/openSUSE_Tumbleweed/network:messaging:matrix.repo
zypper refresh
zypper install python-matrix_common
For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/network:messaging:matrix/openSUSE_Factory/network:messaging:matrix.repo
zypper refresh
zypper install python-matrix_common
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/network:messaging:matrix/16.0/network:messaging:matrix.repo
zypper refresh
zypper install python-matrix_common