source extraction and photometry on all sources
Currently uses SEXTRACTOR for source extraction and for photometry.
The output catalogue is not completely in LCOGT Standard Catalogue Product form and requires post-processing by timecorrect.py in order to propogate the image headers, calculate the missing AIRMASS and TCORR columns and splitting the FLUX_APER and FLUXERR_APER 2D arrays into 8 separate columns.