Fix .mailmap for Jim Zhang
Add Patrick Poitras to .mailmap
Fix .mailmap for Thomas Hisch
Add Sushant Hiray to AUTHORS/aboutus/.mailmap. Welcome to SymPy!
Fix .mailmap for Anurag Sharma
Add Abhinav Chanda to the AUTHORS/aboutus. Welcome to SymPy!
Add Jim Crist to AUTHORS/aboutus/.mailmap. Welcome to SymPy!
Add Sudhanshu Mishra to the AUTHORS/aboutus. Welcome to SymPy!
Add Soumya Dipta Biswas to the AUTHORS/aboutus. Welcome to SymPy!
mailmap_update.py doesn't work for old git versions, warning was added