System tests on travis with MYSQLI are running too long #12691

In most cases the build is currently failing as the system tests for mysqli get terminated after 40min.
For testing purpose I added a small script to check the running times of tests > 5 sec:

https://travis-ci.org/matomo-org/matomo/jobs/360648037

Tests running very long are:

• Test Piwik\Tests\System\ArchiveCronTest::testArchivePhpCron took 438.5 seconds
• ​​​​​​​​Test Piwik\Tests\System\ArchiveWebTest::test_WebArchiveScriptCanBeRun_WithPhpCgi_AndWithoutTokenAuth took 466.8 seconds

Setup of the fixture MaySitesImportedLogs only takes ~30 sec, but contains a lot of data. Maybe we should use a smaller fixture for those tests to run faster?

And some of the API tests Piwik\Tests\System\AutoSuggestAPITest::testAnotherApi take alomst 60sec

ArchiveWebTest moved to Integration tests for now, so tests are passing again. Nevertheless we should check if we can improve the Archiving tests to run faster...