Update README.md

Author: samsonjs

README.md

@@ -209,8 +209,8 @@ After checking out the repo, run `bin/setup` to install dependencies. Then, run
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release` to create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
 
-For maintainers releasing a new version, please see [Releasing.md](Releasing.md).
+For maintainers releasing a new version, please see [RELEASING.md](RELEASING.md).
 
 ## Contributing
 
-See [Contributing.md](Contributing.md).
+See [CONTRIBUTING.md](CONTRIBUTING.md).