More tests

• I'll add a coverage report to tests [1];
• I'll try to make the tests a little bit faster;
• break the test-ci.sh into a couple of smaller files.

I'm adding the new files to the extra sub-folder. Add F27 is not a bad idea.

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[1] That said, the running tests are "heavy" to the bot build. At least for now I do not intend to suggest more tests.