pssh from network:ha-clustering:Stable project

需要 CentOS 7 ，用 root 執行：

cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/network:ha-clustering:Stable/CentOS_7/network:ha-clustering:Stable.repo
yum install pssh

需要 openSUSE Tumbleweed ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/network:ha-clustering:Stable/openSUSE_Tumbleweed/network:ha-clustering:Stable.repo
zypper refresh
zypper install pssh

需要 15.6 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/network:ha-clustering:Stable/15.6/network:ha-clustering:Stable.repo
zypper refresh
zypper install pssh

需要 15.5 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/network:ha-clustering:Stable/15.5/network:ha-clustering:Stable.repo
zypper refresh
zypper install pssh

需要 RHEL 7 ，用 root 執行：

cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/network:ha-clustering:Stable/RHEL_7/network:ha-clustering:Stable.repo
yum install pssh

需要 ScientificLinux 7 ，用 root 執行：

cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/network:ha-clustering:Stable/ScientificLinux_7/network:ha-clustering:Stable.repo
yum install pssh