Bump puma from 3.12.4 to 5.6.7

Bumps [puma](https://github.com/puma/puma) from 3.12.4 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@v3.12.4...v5.6.7)

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

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

Gemfile

@@ -4,7 +4,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 ruby '2.6.6'
 
 gem 'rails', '~> 5.2.4', '>= 5.2.4.2'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 5.6'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 gem 'coffee-rails', '~> 4.2'

Gemfile.lock

@@ -102,7 +102,8 @@ GEM
     nio4r (2.5.2)
     nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.4)
+    puma (5.6.7)
+      nio4r (~> 2.0)
     raabro (1.1.6)
     rack (2.2.2)
     rack-protection (2.0.8.1)
@@ -222,7 +223,7 @@ DEPENDENCIES
   byebug
   coffee-rails (~> 4.2)
   jbuilder (~> 2.5)
-  puma (~> 3.11)
+  puma (~> 5.6)
   rails (~> 5.2.4, >= 5.2.4.2)
   resque (~> 1.27.4)
   resque-scheduler