The <section name="oracle.manageddataaccess....> XML gets added as part of the install process. You don't seem to have run the installer on your testing machine, which is the reason for the error. My suggested solution is to just run the installer on your testing machine and you should be fine. If you want to install via xcopy, that's fine. Just don't forget to run the configuration script.
The other way to ensure your app.configs are the same is to move the XML you added to the app.config to the machine.config. You would then be able to have the same app.config info...and even the same machine.config info presumably.