configuration to disable api key support (#123)

## Problem

A user cannot use all the features of the library without also using the API Key auth features.

## Solution

```ruby
Stitches.configure do |config|
  config.disable_api_key_support = true
end
```

lib/stitches/api_key.rb

@@ -23,6 +23,8 @@ class ApiKey < Stitches::AllowlistMiddleware
   protected
 
     def do_call(env)
+      return @app.call(env) if Stitches.configuration.disable_api_key_support
+
       authorization = env["HTTP_AUTHORIZATION"]
       if authorization
         if authorization =~ /#{configuration.custom_http_auth_scheme}\s+key=(.*)\s*$/

lib/stitches/configuration.rb

@@ -17,9 +17,10 @@ def reset_to_defaults!
     @max_cache_size = NonNullInteger.new("max_cache_size", 0)
     @disabled_key_leniency_in_seconds = ActiveSupport::Duration.days(3)
     @disabled_key_leniency_error_log_threshold_in_seconds = ActiveSupport::Duration.days(2)
+    @disable_api_key_support = false
   end
 
-  attr_accessor :disabled_key_leniency_in_seconds, :disabled_key_leniency_error_log_threshold_in_seconds
+  attr_accessor :disabled_key_leniency_in_seconds, :disabled_key_leniency_error_log_threshold_in_seconds, :disable_api_key_support
 
   # A RegExp that allows URLS around the mime type and api key requirements.
   # nil means that ever request must have a proper mime type and api key.