[tut] ensure_throws should also process tut::failure

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[tests] ensure_op tests

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
rpm: execute unit tests in %check

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>