replaced xargs by standard pip install for all steps it is not required (keep only for tests from scratch) to save time

cartopy 0.18 has problems when installing numpy at the same time, change to xargs installation (line by line pip install)

split experiment path and name setup, replace parser inside ExpSetup by experiment_date parameter and add therefore args handling to all run scripts

refactored python3 -> 3.6, add test_type variable to pytest to differ between different test types (on gpu, from scratch, ...)