[dev] Un-skip some tests

[lionel-bijaoui]

While doing #121 , I have skipped a few test for fieldDateTimePicker.spec.js.
I has to do with the recent change to fecha instead of moment.
At the time, I didn't want to take care of it, but it is a thing to fix.

While at it, I could be a good time to check if the unit tests are still up-to-date.