Because the test is added by default, and run by default in GitLab CI,
this means that by default the test will fail.

With this change, the test fails in 10 seconds instead of 15 minutes,
leaving more time for other jobs.

The simulator was rewritten in Lewis, which changed its default port to
9999, and is now case-sensitive.

Renamed to "Adding integration tests to your IOC", because an
"Integration tests" user guide is planned, and to make it a bit clearer
that it is a continuation of the StreamDevice tutorial.

Previously the tutorial was a mix between a guide and tutorial, not
really guided enough.

Now the tutorial builds upon the StreamDevice tutorial, and shows a
complete path to have a fully functional integration test.

Also introduce how to *run* tests, both non-interactively and
interactively.

Added a quick reference of useful Python test functions.

The tutorial was also updated due to some changes in the default
template, and some renamed options.

Nix will show an error running tests if KVM is not present.