Update dependency rack to v2.2.18 [SECURITY]

Author: renovate[bot]

Gemfile

@@ -16,7 +16,7 @@ gem 'loog', '~>0.2'
 gem 'minitest', '~>5.16', require: false
 gem 'minitest-reporters', '~>1.5', require: false
 gem 'pgtk', '~>0.7'
-gem 'rack', '2.1.4.1'
+gem 'rack', '2.2.18'
 gem 'rack-ssl', '~>1.4'
 gem 'rack-test', '~>1.1'
 gem 'rake', '~>12.3', require: false

Gemfile.lock

@@ -119,7 +119,7 @@ GEM
     plist (3.1.0)
     powerpack (0.1.3)
     racc (1.7.1)
-    rack (2.1.4.1)
+    rack (2.2.18)
     rack-protection (2.0.4)
       rack
     rack-ssl (1.4.1)
@@ -174,6 +174,11 @@ GEM
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.4.0)
+    rubocop-minitest (0.0.1)
+    rubocop-performance (1.0.0)
+      rubocop (>= 0.58.0)
+    rubocop-rake (0.5.1)
+      rubocop
     rubocop-rspec (1.30.1)
       rubocop (>= 0.60.0)
     ruby-progressbar (1.13.0)
@@ -288,38 +293,41 @@ PLATFORMS
 
 DEPENDENCIES
   bundler (~> 2.3)
-  codecov (= 0.2.8)
-  eslintrb (= 2.1.0)
-  glogin (= 0.10.0)
-  haml (= 5.0.4)
-  iri (= 0.5.0)
-  loog (= 0.2.1)
-  minitest (= 5.16.3)
-  minitest-reporters (= 1.5.0)
-  pgtk (= 0.7.5)
-  rack (= 2.1.4.1)
-  rack-ssl (= 1.4.1)
-  rack-test (= 1.1.0)
-  rake (= 12.3.3)
-  redcarpet (= 3.5.1)
-  relative_time (= 1.1.0)
-  rerun (= 0.13.1)
-  rspec-rails (= 3.8.1)
-  rubocop (= 0.62.0)
-  rubocop-rspec (= 1.30.1)
-  sass (= 3.7.2)
-  sentry-raven (= 2.7.4)
-  sinatra (= 2.0.4)
-  sinatra-contrib (= 2.0.4)
-  sprockets (= 3.7.2)
-  tacky (= 0.3.5)
+  codecov (~> 0.2)
+  eslintrb (~> 2.1)
+  glogin (~> 0.10)
+  haml (~> 5.0)
+  iri (~> 0.5)
+  loog (~> 0.2)
+  minitest (~> 5.16)
+  minitest-reporters (~> 1.5)
+  pgtk (~> 0.7)
+  rack (= 2.2.18)
+  rack-ssl (~> 1.4)
+  rack-test (~> 1.1)
+  rake (~> 12.3)
+  redcarpet (~> 3.5)
+  relative_time (~> 1.1)
+  rerun (~> 0.13)
+  rspec-rails (~> 3.8)
+  rubocop (~> 0.62)
+  rubocop-minitest (> 0)
+  rubocop-performance (> 0)
+  rubocop-rake (> 0)
+  rubocop-rspec (~> 1.30)
+  sass (~> 3.7)
+  sentry-raven (~> 2.7)
+  sinatra (~> 2.0)
+  sinatra-contrib (~> 2.0)
+  sprockets (~> 3.7)
+  tacky (~> 0.3)
   telepost (>= 0.3.2)
-  thin (= 1.8.2)
+  thin (~> 1.8)
   threads (>= 0.3)
-  veils (= 0.3.0)
-  xcop (= 0.6)
+  veils (~> 0.3)
+  xcop (~> 0.6)
   zache (>= 0.12.0)
-  zold-ruby-sdk (= 0.3.0)
+  zold-ruby-sdk (~> 0.3)
 
 RUBY VERSION
    ruby 2.6.0p0