Bump puma from 3.12.0 to 3.12.2

Bumps [puma](https://github.com/puma/puma) from 3.12.0 to 3.12.2.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v3.12.0...v3.12.2)

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

Author: dependabot[bot]

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', '~> 3.7'
+gem 'puma', '~> 3.12'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets

Gemfile.lock

@@ -95,7 +95,7 @@ GEM
     nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (3.12.2)
     rack (2.0.6)
     rack-proxy (0.6.5)
       rack
@@ -192,7 +192,7 @@ DEPENDENCIES
   coffee-rails (~> 4.2)
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.7)
+  puma (~> 3.12)
   rails (~> 5.1.4)
   react-rails
   sass-rails (~> 5.0)