Introduce CI gating. This will introduce new testcase called
fedora-ci.koji-build.tier0.functional and will configure it
as a mandatory CI gating testcase for elfutils fedora builds.
The provided test case is executed by running ./runtest.sh.
The main.fmf file keeps the testcase metadata. The plans and
.fmf folders contain configuration files needed for execution
of provided testcases within the Fedora CI infrastructure.
The provided testcase relies upon the debuginfod server
providing needed kernel-debuginfo. It was tested with
staging instance of the debuginfod server running at
https://debuginfod.stg.fedoraproject.org/ .
Provided test uses Flexible Metadata Format, as documented in
https://fmf.readthedocs.io/ .
