Minor Leveraging Sauce Labs, make tests run and pass on latest Safari version.
It seems there is an issue with Safari 11.1.0 and CORS when POSTing multipart/form-data on automation endpoint for instance.
It works OK locally on Safari 11.1.2 and 12, but Sauce Labs is currently on 11.1.0.
Wait for the update on Sauce Labs and test it again.
