[SSSD] [sssd PR#181][synchronized] README.md: Point to our releases on pagure

[jhrozek]

URL: https://github.com/SSSD/sssd/pull/181
Author: jhrozek
 Title: #181: README.md: Point to our releases on pagure
Action: synchronized

To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/181/head:pr181
git checkout pr181