Bump puma from 3.12.0 to 3.12.3

Bumps [puma](https://github.com/puma/puma) from 3.12.0 to 3.12.3.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v3.12.0...v3.12.3)

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

Author: dependabot[bot]

Gemfile

@@ -11,7 +11,7 @@ end
 gem 'rails', '~> 5.1.6.2'
 # Use sqlite3 as the database for Active Record
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 3.12'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 

Gemfile.lock

@@ -125,7 +125,7 @@ GEM
     postgresql (1.0.0)
       pg
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (3.12.3)
     rack (2.0.6)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -233,7 +233,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   jquery-rails
   postgresql
-  puma (~> 3.7)
+  puma (~> 3.12)
   rails (~> 5.1.6.2)
   sass-rails (~> 5.0)
   selenium-webdriver