fix(logger): remove priority from log messages

Our current log message follows this format:

    2014-09-02 09:40:00 deis[api]: message

Where `deis[api]` is the tag. Removing the priority keeps the
log message the same format as before.

logger/syslog/message.go

@@ -21,8 +21,7 @@ type Message struct {
 func (m *Message) String() string {
 	timeLayout := "2006-01-02 15:04:05"
 	return fmt.Sprintf(
-		"<%d>%s %s: %s",
-		m.Priority,
+		"%s %s: %s",
 		m.Time.Format(timeLayout),
 		m.Tag,
 		m.Content,

logger/syslog/message_test.go

@@ -9,7 +9,7 @@ func TestMessageFormat(t *testing.T) {
 	m := &Message{time.Now(), 34, time.Now(), "localhost", "test", "hello world"}
 
 	timeLayout := "2006-01-02 15:04:05"
-	expectedOutput := "<34>" + m.Time.Format(timeLayout) + " test: hello world"
+	expectedOutput := m.Time.Format(timeLayout) + " test: hello world"
 	if m.String() != expectedOutput {
 		t.Errorf("expected '" + expectedOutput + "', got '" + m.String() + "'.")
 	}