Add test for saveEventsFile for saving stim files #142
Description
This saveEventsFile will require additional tests to define how it behaves when saving stim files but I am tempted to move that into another PR since the test suite we have requires quite a bit of refactoring anyway.
For example if we want to save an array into a stim files if we have extra columns with several values.
Originally posted by @Remi-Gau in #115 (comment)