CI: Use dnf 2.0 for installation of packages in fedora Weak dependencies are intentionally disabled. If we need them then they should be explicitly specified because they are not weak. Resolves: https://pagure.io/SSSD/sssd/issue/2809 Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>

CI: Use yum-deprecated instead of dnf /usr/bin/yum is provided by the dnf-yum package and call /usr/bin/dnf on new fedora distributions. We should directly use old style yum which was renamed to /usr/bin/yum-deprecated and is still part of the yum package. Reviewed-by: Nikolai Kondrashov <Nikolai.Kondrashov@redhat.com>

CI: Don't depend on user input with apt-get Resolves: https://fedorahosted.org/sssd/ticket/2433 Reviewed-by: Nikolai Kondrashov <Nikolai.Kondrashov@redhat.com>

CI: Don't say Valgrind is ignored in README.md Reviewed-by: Michal Židek <mzidek@redhat.com>

Add basic support for CI test execution Add basic support for executing continuous integration (CI) tests on RHEL6, RHEL7, Fedora 20, Fedora Rawhide and Debian Testing. This adds two front-end scripts which can be executed either locally by developers, or on a CI server: contrib/ci/run and contrib/ci/clean. The first one will run the tests and the second will wipe out the artifacts. See contrib/ci/README.md for further details. Reviewed-by: Michal Židek <mzidek@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>