Add logging message for debug/error

This changes adds logging message:debug and error. fmt.Errorf() is
wrapped by logging.Errorf() hence all error message is also put to
log file. logging.Debugf() is called at almost function call, so
we could track the code by logging message.

logging/logging_test.go

@@ -17,8 +17,8 @@ package logging
 import (
 	"testing"
 
-        . "github.com/onsi/ginkgo"
-        . "github.com/onsi/gomega"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
 )
 
 func TestLogging(t *testing.T) {