Enable initial set of Fedora CI tests
The goal of the Fedora CI is to run "basic functionality" and
"integration" tests. Avocado's gdbtest.py does both, as it exercises
the Avocado test and utils APIs, and also communicates with GDB, thus
ensuring some integration validation with those packages.
Reference: https://fedoraproject.org/wiki/CI
Signed-off-by: Cleber Rosa <crosa@redhat.com>