Use errcheck to find unhandled errors (#795)

Signed-off-by: Chris Cummer <chriscummer@me.com>

logger/log.go

@@ -17,7 +17,7 @@ func Log(msg string) {
 	if err != nil {
 		log.Fatalf("error opening file: %v", err)
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 
 	log.SetOutput(f)
 	log.Println(msg)