Update jbuilder requirement from ~> 2.11.5 to ~> 2.12.0 (#79)

Updates the requirements on [jbuilder](https://github.com/rails/jbuilder) to permit the latest version.
- [Release notes](https://github.com/rails/jbuilder/releases)
- [Commits](rails/jbuilder@v2.11.5...v2.12.0)

---
updated-dependencies:
- dependency-name: jbuilder
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile

@@ -22,7 +22,7 @@ gem "coffee-rails", "~> 5.0.0"
 # Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
 gem "turbolinks", "~> 5.2.1"
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-gem "jbuilder", "~> 2.11.5"
+gem "jbuilder", "~> 2.12.0"
 # Use Redis adapter to run Action Cable in production
 # gem 'redis', '~> 4.0'
 # Use ActiveModel has_secure_password