feat: Provide better Rails cache store support

lib/geocoder/cache.rb

@@ -1,4 +1,4 @@
-Dir["#{__dir__}/cache_stores/*.rb"].each {|file| require file }
+Dir["#{__dir__}/cache_stores/**/*.rb"].each {|file| require file }
 
 module Geocoder
   class Cache

lib/geocoder/cache_stores/active_support/cache/redis_cache_store.rb

@@ -0,0 +1,37 @@
+require 'geocoder/cache_stores/base'
+
+module Geocoder::CacheStore::ActiveSupport::Cache
+  class RedisCacheStore < Geocoder::CacheStore::Base
+    def write(url, value, expires_in = @config[:expiration])
+      if expires_in.present?
+        store.write(key_for(url), value, expires_in: expires_in)
+      else
+        store.write(key_for(url), value)
+      end
+    end
+
+    def read(url)
+      store.read(key_for(url))
+    end
+
+    def keys
+      if store.redis.respond_to?(:with)
+        store.redis.with do |redis|
+          redis.scan_each(match: "#{prefix}*").to_a.uniq
+        end
+      else
+        store.redis.scan_each(match: "#{prefix}*").to_a.uniq
+      end
+    end
+
+    def urls
+      return keys if prefix.blank?
+
+      keys.map { |key| key.delete_prefix(prefix) }
+    end
+
+    def expire_single_url(url)
+      store.delete(key_for(url))
+    end
+  end
+end