Make massmappy an installable package

[EiffL]

In its present form, massmappy is not a proper python package. I have modified the setup.py and moved the source files to an isolated massmappy directory so that it can now be installed easily with the following command:

python setup.py install --user

It shouldn't change the previous behavior, you can still compile the files with python setup.py build_ext --inplace command. The scripts in the src/python folder should work just as before.

I have also added a draft jupyter notebook to demonstrate how massmappy can be used, you may want to add documentation and comments to make it nicer.

With these modifications, and the one I have submitted for ssht, the whole astroinformatics software stack can be installed in a docker container and massmappy can be tried live in a jupyter notebook, see https://github.com/EiffL/astro-informatics-docker for more details.

[EiffL]

Hi @jasonmcewen any update on that PR ?

[jasonmcewen]

Hi @EiffL, @cgrwallis left academia recently for an industry position, hence the reason the PR hasn't been reviewed and merged. Thanks for pinging us. Matt and I will try to look at it this week.