I've been accidentally including my Python virtual environment directory venv in all my git commit and push activity. 
I've just added venv to my .gitignore. But my .git folder is still massive (I'm assuming because of the previous commits and tracking of venv).
How can I get git to totally forget about tracking venv and get my .git folder down to a reasonable size again as it's making Heroku pushes a nightmare. 
 
     
     
     
     
     
    