Deprecate ImageFileCollection and use the one from ccdproc instead

Closes #216

README.rst

@@ -12,7 +12,9 @@ MSUM Astro library
     :target: https://coveralls.io/r/mwcraig/msumastro
 
 
-This software was developed primarily to process the files coming off the Paul P. Feder Observatory at Minnesota State University Moorhead. We needed to do several things:
+This software was developed primarily to process the files coming off the Paul
+P. Feder Observatory at Minnesota State University Moorhead. We needed to do
+several things:
 
 + Add in some essential meta-data (like LST, JD, AIRMASS) that isn't added by the software that grabs the images.
 + Add astrometry using http://astrometry.net
@@ -21,9 +23,13 @@ This software was developed primarily to process the files coming off the Paul P
 There is one generally useful piece: image collections
 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
-Make a collection by providing the name of a directory and a list of the FITS keywords
-you want the collection to make a table of (or ``*`` for all keywords in any of the
-files):
+``ImageFileCollection`` has been moved to `ccdproc
+<https://github.com/astropy/ccdproc>`_. It is marked as deprecated in
+``msumastro`` version 0.9 and will be removed in the next release.
+
+Make a collection by providing the name of a directory and a list of the FITS
+keywords you want the collection to make a table of (or ``*`` for all keywords
+in any of the files):
 
 .. code::