updating ruby rack library version

ruby/Gemfile

@@ -4,3 +4,4 @@ source "https://rubygems.org"
 
 gem 'checkout_sdk', '~> 1.1', '>= 1.1.1'
 gem 'sinatra'
+gem 'rack', '~> 2.2.6.4'

ruby/Gemfile.lock

@@ -20,7 +20,7 @@ GEM
     multipart-post (2.3.0)
     mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.6.2)
+    rack (2.2.6.4)
     rack-protection (3.0.5)
       rack
     ruby2_keywords (0.0.5)
@@ -37,6 +37,7 @@ PLATFORMS
 
 DEPENDENCIES
   checkout_sdk (~> 1.1, >= 1.1.1)
+  rack (~> 2.2.6.4)
   sinatra
 
 BUNDLED WITH

ruby/README.md

@@ -34,7 +34,7 @@ form.addEventListener('submit', function (event) {
 });
 ````
 
-Make sure to provide your correct `Public Key` in `script.js`, which is the key that authorizes to you the access to Checkout API's
+Make sure to provide your correct `Public Key` in `script.js`, which is the key that authorizes to you the access to Checkout API's. This should be stored in a secure location like a password vault and not in code.
 
 ````javascript
 Frames.init('pk_sbox_XXX');