NEW: test_filter_gabella_a_polar ENH:filter_setup
NEW: test_filter_gabella_a_polar ENH:filter_setup

--HG--
branch : feature/eg/gabella_polar

heistermann/wradlib,kmuehlbauer/wradlib,wradlib/wradlib,kmuehlbauer/wradlib,heistermann/wradlib,wradlib/wradlib