code: def update():
      
      with settings(warn_only=True):
          print(cyan('\nInstalling/Updating required packages...'))
  
          pip = local('venv/bin/pip install -U --allow-all-external --src libs -r requirements.txt', capture=True)
          if pip.failed:
              print(red(pip))
              abort("pip exited with return code %i" % pip.return_code)
  
          print(green('Packages requirements updated.'))
docs: Update virtual env with requirements packages.