Update bundler requirement from 2.0.1 to 2.0.2

Updates the requirements on [bundler](https://github.com/bundler/bundler) to permit the latest version.
- [Release notes](https://github.com/bundler/bundler/releases)
- [Changelog](https://github.com/bundler/bundler/blob/master/CHANGELOG.md)
- [Commits](rubygems/bundler@v2.0.1...v2.0.2)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

Gemfile

@@ -1,4 +1,4 @@
 source 'https://rubygems.org' do
-  gem 'bundler', '2.0.1'
+  gem 'bundler', '2.0.2'
   gem 'github_changelog_generator', '1.15.0.pre.rc'
 end