Added a dictionary of keyword arguments for SN models + added code for ROOT output

[soso128]

This pull request contains two commits:

1- Added an argument to generate_time_series and generate_fluence in snowglobes.py: this dictionary allows to give keyword arguments to define SN models (EOS, etc...)

2- Added a new code to get ROOT 2D histograms for the rates, instead of collated text files

[JostMigenda]

Thanks @soso128!

I see you’ve already added the docstrings—excellent! Unfortunately, it looks like you accidentally included some unrelated changes to collate() in 3bc87a4. Once you remove those, I think part 1 looks good.

Regarding part 2: ROOT is a very heavy dependency (in terms of time and disk space to install) and, in my experience, quite fragile when it comes to binary compatibility with different versions of Python. So I would be very hesitant before depending on it for a core feature of SNEWPY. Since this code also appears to duplicate a lot of the code from snewpy.snowglobes.collate(), maybe it would be better to have a sample script in snewpy/python/scripts/ that demonstrates how to take the tables returned by snewpy.snowglobes.collate() and write those to a ROOT file?

[soso128]

Ok, done. Indeed it would be better to write a code in scripts/ for the ROOT output. I'll do this.

[soso128]

I just added a script for the ROOT output (and removed the previous code)

[JostMigenda]

Thanks for moving this to a script! It looks good, I just have a few minor suggestions to make it a little clearer to the user.

[JostMigenda]

All looks good now; many thanks @soso128 for being so responsive! And congratulations on your first contribution to SNEWPY! 🎉