emit status report

[staabm]

when cs2pr completes and no errors/warnings have to be emitted, the screen stays empty.

as a user I dont know whether everything worked well and nothing had to be reported or there was a error and I dont see it.

at best we could emit a processed x errors and y warnings or similar status message at the very end into STDERR, so we dont destory possible consumers of our gihtub-api checks formatted output