Add unit test for spacraft frame fitting

[israelmcmc]

These route is not covered by our test

cosipy/cosipy/threeml/COSILike.py

Lines 258 to 260 in 29ac162

	if self._coordsys == 'spacecraftframe':
	dwell_time_map = self._get_dwell_time_map(coord)
	self._psr[name] = self._dr.get_point_source_response(exposure_map=dwell_time_map)

As described in #486, #443 broke this but it was not caught because of this missing test.

[israelmcmc]

This issue is still open, but the code now lives in a different place

cosipy/cosipy/response/threeml_point_source_response.py

Lines 178 to 187 in 2af7213

	if isinstance(coordsys, SpacecraftFrame):
	# Local coordinates
	dwell_time_map = self._sc_ori.get_dwell_map(coord, nside = self._nside)
	self._psr = PointSourceResponse.from_dwell_time_map(self._data,
	self._response,
	dwell_time_map,
	self._energy_axis,
	self._polarization_axis)