I am helping a lot of people with Teamviewer to straightening out Xcode.
Let me give you a Tip, since this is the number 1 problem.
1. Unzip the Chartboost SDK on your MAC. do NOT unzip on Windows and Transfer to mac.. This will mess up the Structure of Chartboost and you will get xxxxx.h errors
2. Check Copy for Chartboost popup that comes up.. Not just Link the folder
3. Turn Bitcode OFF under the Build Settings. (Change it to All, and halfway you will see the setting)
This should do the trick for now with Xcode 7
As usual, if you still have issues, you can let me know, and I will Teamview with you, to fix the issue. This goes so much faster than spending all day swapping out messages