Use our branch of changelog generator

Because this repo now has many thousands more commits in it, the upstream version of the changelog generator takes a huge amount of time (6+ hours). This uses our branch which makes it far more efficient.

Author: nmburgan

Gemfile

@@ -87,7 +87,7 @@ end
 
 group :release, optional: true do
   gem 'faraday-retry', require: false
-  gem 'github_changelog_generator', require: false
+  gem 'github_changelog_generator', require: false, git: 'https://github.com/voxpupuli/github-changelog-generator', branch: 'avoid-processing-a-single-commit-multiple-time'
 end
 
 if File.exist? "#{__FILE__}.local"