fewer panics

pkg/app/app.go

@@ -67,7 +67,7 @@ func newDevelopmentLogger() *logrus.Logger {
 	}
 	file, err := os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
 	if err != nil {
-		panic("unable to log to file") // TODO: don't panic (also, remove this call to the `panic` function)
+		log.Fatalf("Unable to log to log file: %v", err)
 	}
 	logger.SetOutput(file)
 	return logger