Update Sinatra to latest version

This also required bumping Rack which also required bumping Puma.
rackup is now also its own gem so that has been added explicitly.

Author: jasoncodes

Gemfile

@@ -8,6 +8,7 @@ gem 'dalli'
 gem 'memcachier'
 gem 'puma'
 gem 'base64'
+gem 'rackup'
 
 group :development do
   gem 'pry'

Gemfile.lock

@@ -12,22 +12,27 @@ GEM
     memcachier (0.0.2)
     method_source (0.7.1)
     mini_portile2 (2.8.6)
-    mustermann (2.0.2)
+    mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
-    nio4r (2.7.3)
+    nio4r (2.7.4)
     nokogiri (1.16.5)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     pry (0.9.8.4)
       coderay (~> 1.0.5)
       method_source (~> 0.7.1)
       slop (>= 2.4.4, < 3)
-    puma (5.6.9)
+    puma (6.4.3)
       nio4r (~> 2.0)
     racc (1.7.3)
-    rack (2.2.8.1)
-    rack-protection (2.2.3)
-      rack
+    rack (3.1.8)
+    rack-protection (4.0.0)
+      base64 (>= 0.1.0)
+      rack (>= 3.0.0, < 4)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
+    rackup (2.2.0)
+      rack (>= 3)
     rspec (2.11.0)
       rspec-core (~> 2.11.0)
       rspec-expectations (~> 2.11.0)
@@ -39,13 +44,14 @@ GEM
     rspec-mocks (2.11.3)
     ruby-progressbar (0.0.10)
     ruby2_keywords (0.0.5)
-    sinatra (2.2.3)
-      mustermann (~> 2.0)
-      rack (~> 2.2)
-      rack-protection (= 2.2.3)
+    sinatra (4.0.0)
+      mustermann (~> 3.0)
+      rack (>= 3.0.0, < 4)
+      rack-protection (= 4.0.0)
+      rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
     slop (2.4.4)
-    tilt (2.0.11)
+    tilt (2.4.0)
 
 PLATFORMS
   ruby
@@ -58,6 +64,7 @@ DEPENDENCIES
   nokogiri
   pry
   puma
+  rackup
   rspec
   sinatra