Bump rack from 2.0.7 to 2.0.8 in /11.app-final/rails-app

Bumps [rack](https://github.com/rack/rack) from 2.0.7 to 2.0.8.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rack/rack/compare/2.0.7...2.0.8)
Signed-off-by: dependabot[bot] <support@github.com>

11.app-final/rails-app/Gemfile.lock

@@ -104,12 +104,13 @@ GEM
     mini_portile2 (2.4.0)
     minitest (5.11.3)
     msgpack (1.2.10)
+    mysql2 (0.5.3)
     nio4r (2.3.1)
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
     public_suffix (3.1.0)
     puma (3.12.1)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-proxy (0.6.5)
       rack
     rack-test (1.1.0)
@@ -175,7 +176,6 @@ GEM
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
-    sqlite3 (1.4.1)
     thor (0.20.3)
     thread_safe (0.3.6)
     tilt (2.0.9)
@@ -214,13 +214,13 @@ DEPENDENCIES
   image_processing (~> 1.2)
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
+  mysql2
   puma (~> 3.11)
   rails (~> 6.0.0.rc1)
   sass-rails (~> 5)
   selenium-webdriver
   spring
   spring-watcher-listen (~> 2.0.0)
-  sqlite3 (~> 1.4)
   turbolinks (~> 5)
   tzinfo-data
   web-console (>= 3.3.0)