Improved the wavelength calibration routine. It's now possible to fit the
wavelength solution using a polynomial of arbitrary order. Also, the
wavelength solution is also stored in the stellar object, whereas previously
it was only being used to update the existing spectra files.
Trying to sync things again
Merge branch 'master' of https://github.com/tomevans/spectroscopy
    Improved the wavelength calibration routine. It's now possible to fit the
    wavelength solution using a polynomial of arbitrary order. Also, the
    wavelength solution is also stored in the stellar object, whereas previously
    it was only being used to update the existing spectra files.