[changelog skip] Fix Escaping in Changelog Script
[changelog skip] Fix Escaping in Changelog Script

The previous PR had a bug where the REGEX for grep was not properly escaped. This PR fixes that issue.

Scalingo/python-buildpack,AltSchool/heroku-buildpack-python,AltSchool/heroku-buildpack-python,Scalingo/python-buildpack,heroku/heroku-buildpack-python,skilljar/heroku-buildpack-python,benmurden/heroku-buildpack-python-ember,benmurden/heroku-buildpack-python-ember,heroku/heroku-buildpack-python