Update rails past 5.2.5 to work around yanked mimemagic

See these links for context:
* rails/rails#41750
* https://rubyonrails.org/2021/3/26/marcel-upgrade-releases

gemfiles/rails_5.2_no_sprockets.gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: ..
   specs:
-    react-rails (2.6.1)
+    react-rails (2.6.2)
       babel-transpiler (>= 0.7.0)
       connection_pool
       execjs
@@ -11,43 +11,43 @@ PATH
 GEM
   remote: http://rubygems.org/
   specs:
-    actioncable (5.2.4.1)
-      actionpack (= 5.2.4.1)
+    actioncable (5.2.8.1)
+      actionpack (= 5.2.8.1)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
-    actionmailer (5.2.4.1)
-      actionpack (= 5.2.4.1)
-      actionview (= 5.2.4.1)
-      activejob (= 5.2.4.1)
+    actionmailer (5.2.8.1)
+      actionpack (= 5.2.8.1)
+      actionview (= 5.2.8.1)
+      activejob (= 5.2.8.1)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 2.0)
-    actionpack (5.2.4.1)
-      actionview (= 5.2.4.1)
-      activesupport (= 5.2.4.1)
+    actionpack (5.2.8.1)
+      actionview (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
       rack (~> 2.0, >= 2.0.8)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.2.4.1)
-      activesupport (= 5.2.4.1)
+    actionview (5.2.8.1)
+      activesupport (= 5.2.8.1)
       builder (~> 3.1)
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (5.2.4.1)
-      activesupport (= 5.2.4.1)
+    activejob (5.2.8.1)
+      activesupport (= 5.2.8.1)
       globalid (>= 0.3.6)
-    activemodel (5.2.4.1)
-      activesupport (= 5.2.4.1)
-    activerecord (5.2.4.1)
-      activemodel (= 5.2.4.1)
-      activesupport (= 5.2.4.1)
+    activemodel (5.2.8.1)
+      activesupport (= 5.2.8.1)
+    activerecord (5.2.8.1)
+      activemodel (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
       arel (>= 9.0)
-    activestorage (5.2.4.1)
-      actionpack (= 5.2.4.1)
-      activerecord (= 5.2.4.1)
-      marcel (~> 0.3.1)
-    activesupport (5.2.4.1)
+    activestorage (5.2.8.1)
+      actionpack (= 5.2.8.1)
+      activerecord (= 5.2.8.1)
+      marcel (~> 1.0.0)
+    activesupport (5.2.8.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
@@ -84,19 +84,19 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.1.5)
+    concurrent-ruby (1.1.10)
     connection_pool (2.2.2)
-    crass (1.0.5)
+    crass (1.0.6)
     docile (1.1.5)
-    erubi (1.9.0)
+    erubi (1.11.0)
     es5-shim-rails (4.0.1)
       actionpack (>= 3.1)
       railties (>= 3.1)
     execjs (2.7.0)
     ffi (1.11.3)
     formatador (0.2.5)
-    globalid (0.4.2)
-      activesupport (>= 4.2.0)
+    globalid (0.6.0)
+      activesupport (>= 5.0)
     guard (2.16.1)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
@@ -110,31 +110,30 @@ GEM
     guard-minitest (2.4.6)
       guard-compat (~> 1.2)
       minitest (>= 3.0)
-    i18n (1.7.0)
+    i18n (1.12.0)
       concurrent-ruby (~> 1.0)
     jbuilder (2.9.1)
       activesupport (>= 4.2.0)
     json (2.3.0)
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    loofah (2.4.0)
+    loofah (2.18.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lumberjack (1.0.13)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
-    marcel (0.3.3)
-      mimemagic (~> 0.3.2)
+    marcel (1.0.2)
     method_source (0.9.2)
-    mimemagic (0.3.10)
-    mini_mime (1.0.2)
-    mini_portile2 (2.4.0)
-    minitest (5.13.0)
+    mini_mime (1.1.2)
+    mini_portile2 (2.8.0)
+    minitest (5.16.3)
     nenv (0.3.0)
-    nio4r (2.5.2)
-    nokogiri (1.10.7)
-      mini_portile2 (~> 2.4.0)
+    nio4r (2.5.8)
+    nokogiri (1.13.8)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
     notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
@@ -145,34 +144,35 @@ GEM
       byebug (~> 11.0)
       pry (~> 0.10)
     public_suffix (4.0.2)
-    rack (2.0.8)
+    racc (1.6.0)
+    rack (2.2.4)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
-    rails (5.2.4.1)
-      actioncable (= 5.2.4.1)
-      actionmailer (= 5.2.4.1)
-      actionpack (= 5.2.4.1)
-      actionview (= 5.2.4.1)
-      activejob (= 5.2.4.1)
-      activemodel (= 5.2.4.1)
-      activerecord (= 5.2.4.1)
-      activestorage (= 5.2.4.1)
-      activesupport (= 5.2.4.1)
+    rails (5.2.8.1)
+      actioncable (= 5.2.8.1)
+      actionmailer (= 5.2.8.1)
+      actionpack (= 5.2.8.1)
+      actionview (= 5.2.8.1)
+      activejob (= 5.2.8.1)
+      activemodel (= 5.2.8.1)
+      activerecord (= 5.2.8.1)
+      activestorage (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
       bundler (>= 1.3.0)
-      railties (= 5.2.4.1)
+      railties (= 5.2.8.1)
       sprockets-rails (>= 2.0.0)
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.3.0)
+    rails-html-sanitizer (1.4.3)
       loofah (~> 2.3)
-    railties (5.2.4.1)
-      actionpack (= 5.2.4.1)
-      activesupport (= 5.2.4.1)
+    railties (5.2.8.1)
+      actionpack (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
       method_source
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
-    rake (13.0.1)
+    rake (13.0.6)
     rb-fsevent (0.10.3)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
@@ -187,26 +187,29 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sprockets (4.0.0)
+    sprockets (4.1.1)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.1)
-      actionpack (>= 4.0)
-      activesupport (>= 4.0)
+    sprockets-rails (3.4.2)
+      actionpack (>= 5.2)
+      activesupport (>= 5.2)
       sprockets (>= 3.0.0)
     test-unit (2.5.5)
-    thor (1.0.1)
+    thor (1.2.1)
     thread_safe (0.3.6)
     tilt (2.0.10)
-    tzinfo (1.2.6)
+    turbolinks (5.2.1)
+      turbolinks-source (~> 5.2)
+    turbolinks-source (5.2.0)
+    tzinfo (1.2.10)
       thread_safe (~> 0.1)
     webdrivers (4.2.0)
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
       selenium-webdriver (>= 3.0, < 4.0)
-    websocket-driver (0.7.1)
+    websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.4)
+    websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
 
@@ -229,7 +232,8 @@ DEPENDENCIES
   react-rails!
   selenium-webdriver
   test-unit (~> 2.5)
+  turbolinks
   webdrivers
 
 BUNDLED WITH
-   2.1.2
+   2.1.4