Update ewokscore version

Version 1.2.0 brings improvements to ewokssphinx:

Module patterns can be used as argument of discover_tasks_from_modules

So we can get rid of the use of ewokscore private members. Fixes #5 (closed)

Fix random order in required_input_names, optional_input_names and output_names fields of discovered tasks of class type

!3 (comment 396241)