Add scisys receiver

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>
Change description in setup.py

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>
Add scisys test to test bench.

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>
Update producer for new metadata standard.

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>