kasperschmidt/TDOSE: TDOSE version 3.1

TDOSE version 3.1 adds bug fixes and makes TDOSE Python 3 compatible. Improvements compared to TDOSE version 3.0 described in Schmidt et al. (2019) include: Python 3 compatibility Replacing the depreciated Pyfits with astropy.io.fits Introducing subdirectory tdose_examples with executable script, input data, and comparison data for testing TDOSE Function to enable stripping extensions from fits files to enable removing cube extensions from 1D spectra Better handling of contamination modeling when inserting point sources for extraction Fix of bug where NaNs were not propagated correctly in masked arrays when vstacking Change the filling in noise calculations from 0s to NaNs Better handling of singular matrices in flux scalin