[SourcesManager] Adapt for YAMLHelper changes

Gemfile.lock

 GIT
   remote: https://github.com/CocoaPods/CLAide.git
-  revision: 2d1ade5e062be937e630920c7399dbe1bee48d93
+  revision: e64c76edd9dbc540776772097b78ae27720eccbb
   branch: master
   specs:
     claide (0.6.1)
 
 GIT
   remote: https://github.com/CocoaPods/Core.git
-  revision: 54327d78336f93e2301d1e8bf1c637c1a3271892
+  revision: 75028fcea7c8e02cff17ada95bb17f123ac949cc
   branch: master
   specs:
     cocoapods-core (0.33.1)

lib/cocoapods/sources_manager.rb

@@ -269,8 +269,7 @@ module Pod
         yaml_file  = dir + 'CocoaPods-version.yml'
         return {} unless yaml_file.exist?
         begin
-          yaml = Pathname.new(yaml_file).read
-          YAMLHelper.load(yaml)
+          YAMLHelper.load_file(yaml_file)
         rescue Informative => e
           raise Informative, "There was an error reading '#{yaml_file}'.\n" \
             'Please consult http://blog.cocoapods.org/' \

spec/unit/sources_manager_spec.rb

@@ -154,7 +154,7 @@ module Pod
       end
 
       it 'raises when reading version information with merge conflict' do
-        Pathname.any_instance.stubs(:read).returns(merge_conflict_version_yaml)
+        File.stubs(:read).returns(merge_conflict_version_yaml)
         e = lambda { SourcesManager.version_information(SourcesManager.master_repo_dir) }.should.raise Informative
         e.message.should.match /Repairing-Our-Broken-Specs-Repository/
       end