Hot fix: Timer at the end of tests in test_CST_MicrowaveStudio

While working on the tests for #5 (closed) I found out that if we do not wait some seconds between sending the close project or close app command to CST and the end of the test, it is not marked as successful. Apparently, a good amount of time is 5 seconds, although this might change depending on the computer on which we perform the test.

All tests from now on should take this into account. Tests that have been developed before this have to be fixed.