Only report in-app culprits.
Only report in-app culprits.

Closes cupcake/raven-go#16.

Condense initializer

bigdrum/raven-go,getsentry/raven-go,getsentry/raven-go,DramaFever/raven-go,mpuncel/raven-go,bigdrum/raven-go,DramaFever/raven-go,Invacio/raven-go,mpuncel/raven-go