Updated HTTP provider to use slice settings for timeout configuration

Ensures this provider uses the slice settings as defaults so none of this is hard coded. This also allows folks to tweak these settings via the environment variables (as mentioned in the previous commit).

Issue: 309
Milestone: minor

config/providers/http.rb

@@ -9,8 +9,12 @@ Hanami.app.register_provider :http do
   start do
     slice.start :logger
 
+    connect, read, write = slice[:settings].to_h.values_at :http_timeout_connect,
+                                                           :http_timeout_read,
+                                                           :http_timeout_write
+
     http = ConnectionPool::Wrapper.new size: ENV.fetch("HANAMI_MAX_THREADS", 5) do
-      HTTP.timeout(connect: 2, read: 10, write: 10)
+      HTTP.timeout(connect:, read:, write:)
           .use(:auto_inflate)
           .use(logging: {logger: slice[:logger]})
           .headers("User-Agent" => "http.rb/#{HTTP::VERSION} (#{Hanami.app.app_name})")