Do not cache runkit

The improvement is not noticeable in this case, so let's always use
fresh copy.

Signed-off-by: Michal Čihař <michal@cihar.com>
Supress success output from lint

Signed-off-by: Michal Čihař <michal@cihar.com>
Merge lint run into testsuite run

It should be faster to run these in parallel, but given limited amount
of workers, it's better to do more work in single run. The run takes
longer, but overall time to run all tests is lower due to less waiting
for free worker.

Signed-off-by: Michal Čihař <michal@cihar.com>