[Integration] Support running with multiple psych versions

spec/integration.rb

@@ -91,6 +91,18 @@ CLIntegracon.configure do |c|
     path.open('w') { |f| f << Pod::YAMLHelper.convert_hash(yaml, keys_hint, "\n\n") }
   end
 
+  c.preprocess('**/*.xcodeproj', %r{(^|/)(Podfile|Manifest).lock$}) do |path|
+    keys_hint = if path.extname == '.lock'
+                  Pod::Lockfile::HASH_KEY_ORDER
+                end
+    contents = path.read
+    if contents.strip.empty?
+      contents
+    else
+      Pod::YAMLHelper.convert_hash(YAML.load(contents), keys_hint, "\n\n")
+    end
+  end
+
   # So we don't need to compare them directly
   c.ignores 'Podfile'