Bump puma from 3.12.2 to 5.6.7 in /examples/rails-custom-login-page

Bumps [puma](https://github.com/puma/puma) from 3.12.2 to 5.6.7.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v3.12.2...v5.6.7)

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

Signed-off-by: dependabot[bot] <support@github.com>

examples/rails-custom-login-page/Gemfile

@@ -11,7 +11,7 @@ gem 'rails', '~> 5.1.4'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 5.6'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets

examples/rails-custom-login-page/Gemfile.lock

@@ -104,7 +104,8 @@ GEM
       httparty (>= 0.13.7)
       nokogiri (>= 1.6.3.1)
     public_suffix (3.0.2)
-    puma (3.12.2)
+    puma (5.6.7)
+      nio4r (~> 2.0)
     rack (2.0.8)
     rack-test (0.8.3)
       rack (>= 1.0, < 3)
@@ -195,8 +196,8 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   jquery-rails
   listen (>= 3.0.5, < 3.2)
-  onelogin (~> 1.5.0)
-  puma (~> 3.12)
+  onelogin (~> 1.6.0)
+  puma (~> 5.6)
   rails (~> 5.1.4)
   sass-rails (~> 5.0)
   selenium-webdriver