Undo adding image collection to work unit. That needs refactoring som…

…ewhere else.

src/kbmod/image_collection.py

@@ -878,5 +878,5 @@ def toWorkUnit(self, search_config=None, **kwargs):
                 layeredImages.append(img)
         imgstack = ImageStack(layeredImages)
         if None not in self.wcs:
-            return WorkUnit(imgstack, search_config, per_image_wcs=list(self.wcs), collection=self)
+            return WorkUnit(imgstack, search_config, per_image_wcs=list(self.wcs))
         return WorkUnit(imgstack, search_config)

src/kbmod/work_unit.py

@@ -1,7 +1,10 @@
+import math
 import os
 
 from astropy.io import fits
+from astropy.table import Table
 from astropy.utils.exceptions import AstropyWarning
+from astropy.wcs import WCS
 from astropy.wcs.utils import skycoord_to_pixel
 from astropy.time import Time
 from astropy.coordinates import SkyCoord, EarthLocation
@@ -12,7 +15,6 @@
 
 from kbmod.configuration import SearchConfiguration
 from kbmod.search import ImageStack, LayeredImage, PSF, RawImage, Logging
-
 from kbmod.wcs_utils import (
     append_wcs_to_hdu_header,
     extract_wcs_from_hdu_header,