[Resolved] warning: calling URI.open via Kernel#open is deprecated

```
warning: calling URI.open via Kernel#open is deprecated, call URI.open directly or use URI#open
```

lib/itest5ch/http_methods.rb

@@ -12,7 +12,7 @@ def get_html(url, referer: nil)
       options["User-Agent"] = Itest5ch.config.user_agent if Itest5ch.config.user_agent
       options["Referer"] = referer if referer
 
-      open(url, options).read # rubocop:disable Security/Open
+      URI.open(url, options).read
     end
 
     # @param url [String]