To use two Facebook app ids on the same app for testing

In order to test Facebook Events without modify the production data I need to use a second Facebook App Id inside of my iOS app. I want to do that automatically my Continuous Integration environment.

• Release Scheme -> Will have production Facebook app id.
• Debug Scheme -> Will have debug Facebook app id.

Do you use a pre-building script to modify the info.plist file? Do you know a better way to solve this problem?