Factor out code lint

Now we can share it for different CI platforms

Signed-off-by: Michal Čihař <michal@cihar.com>
Share script for running tests

This makes it also easy to read than script in yml

Signed-off-by: Michal Čihař <michal@cihar.com>
Share environment setup between CIs

Signed-off-by: Michal Čihař <michal@cihar.com>
Force MySQL to use UTF-8 for testing

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