Allowing Airbrake-iOS to be used with OS X

Even thought it's named Airbrake-iOS, it works with OS X too.  They have an OS X sample project in their repo:
https://github.com/airbrake/airbrake-ios/tree/master/Xcode/Hoptoad%20Mac
Merge pull request #5083 from pyro2927/patch-2

Allowing Airbrake-iOS to be used with OS X