Description

Include git commit in package and model meta

• save current git commit in spacy/git_info.py
• include current git commit in meta.json when models are saved
• git version code in setup.py is adapted from numpy, add licenses/3rd_party_licenses.txt with relevant license

Types of change

Enhancement

Checklist

• I have submitted the spaCy Contributor Agreement.
• I ran the tests, and all new and existing tests passed.
• My changes don't require a change to the documentation, or if they do, I've added all required information.