Remove pyfits

[saimn]

Hi Ole,

This is to remove the Pyfits dependency from python-cpl, because:

• PyFITS is deprecated and no longer supported: https://github.com/spacetelescope/pyfits
• I'm having trouble with installing python-cpl in a fresh virtualenv (with tox), which requires Pyfits as Astropy is not yet installed in the virtualenv, and Pyfits installation crashes on Python 3.6...

[saimn]

BTW, it could a good occasion to update the Travis test matrix, adding Python 3.6 and 3.7, and removing 3.3 ?

[coveralls]

Coverage increased (+0.6%) to 77.095% when pulling d98bcd0578c038856c38032aa8ae414e370a343a on saimn:remove-pyfits into 52217daeff1bd1bfc92ccbdf08e7382fb03f32ec on olebole:master.

[coveralls]

Coverage increased (+0.2%) to 76.659% when pulling a02711452a6e4cedd706d9f6e322d0256220d479 on saimn:remove-pyfits into 52217daeff1bd1bfc92ccbdf08e7382fb03f32ec on olebole:master.

[saimn]

Astropy >3.0 requires Python 3.5+, making the 3.3 and 3.4 builds fail:

Collecting astropy
  Downloading https://files.pythonhosted.org/packages/fc/36/26114bb003bc1ebb483a6fa1da7bb88868c87a80327c9f0c0b1c4b9c3dbc/astropy-3.0.3.tar.gz (8.1MB)
    100% |████████████████████████████████| 8.1MB 183kB/s 
    Complete output from command python setup.py egg_info:
    ERROR: Astropy requires Python 3.5 or later

[saimn]

So I removed 3.3 (for which there may be an issue with python_requires, I don't know, but anyway I think it can safely be dropped), and added 3.6. For 3.7, last time I looked Travis was not yet handling it well (I think you need to use a more recent Ubuntu version with the dist: keyword, but I haven't tried yet).

[olebole]

I completely agree with you; thank you for the patch.

[saimn]

@olebole - Would be great if you could do a new release with this and #9 :slightly_smiling_face: . I can help a bit if you need.

[olebole]

Yep, I will do this week. Just still processing my Debian-backlog with the Python 3.7 conversion. Is there anything else you think should be added to a new release?

[saimn]

Ok thanks. I see nothing particular in terms of features, but the packaging might need some updates (switch to setuptools and use python_requires to prepare a future Python 2 support removal - https://hackernoon.com/phasing-out-python-runtimes-gracefully-956f112f33c4 - , update url and download_url).

[olebole]

OK; so if you like you can prepare some PRs; this would speed up the process.