We are having the same issue found here, here, here and here
Basically we upgraded to xcode 6.1 and our build are getting the \"ResourceRules.plist: cannot read reso
We are using Unity + Jenkins for auto builds.
You can achieve with post process cs scripts; however; for quick (and dirty fix) you can apply following bash command after Unity but before xcode:
sed -i '' 's/CONFIGURATION_BUILD_DIR/CODE_SIGN_RESOURCE_RULES_PATH = "\$(SDKROOT)\/ResourceRules\.plist";\'$'\n CONFIGURATION_BUILD_DIR/g' /Users/admin/Jenkins/workspace/PROJECTNAME/Build/PROJECTNAME/Unity-iPhone.xcodeproj/project.pbxproj