Bump puma from 4.3.5 to 4.3.8

Bumps [puma](https://github.com/puma/puma) from 4.3.5 to 4.3.8.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v4.3.5...v4.3.8)

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

Gemfile

@@ -86,7 +86,7 @@ gem 'jquery-rails', '~> 4.3'
 
 # Moku freeze
 gem 'nio4r', '= 2.5.1'
-gem 'puma', '4.3.5'
+gem 'puma', '4.3.8'
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console

Gemfile.lock

@@ -162,7 +162,7 @@ GEM
       ast (~> 2.4.1)
     popper_js (1.16.0)
     public_suffix (4.0.5)
-    puma (4.3.5)
+    puma (4.3.8)
       nio4r (~> 2.0)
     raabro (1.3.1)
     racc (1.5.2)
@@ -331,7 +331,7 @@ DEPENDENCIES
   marc (~> 1.0)
   mysql2 (~> 0.4.10)
   nio4r (= 2.5.1)
-  puma (= 4.3.5)
+  puma (= 4.3.8)
   rails (~> 5.2.4.3)
   rspec-rails (~> 4.0)
   rubocop-performance (~> 1.2)