make sure no leading or trailing spaces

This changed printColored and printKeyValue to print in same way
with prefix space instead of trailing space, to make it easier
to slice out when returning in Format;
The test cases are to make sure msg formartting doesn't include
leading or trailing spaces;

Closes #99

Signed-off-by: Derek Che <drc@yahoo-inc.com>

text_formatter.go

@@ -69,7 +69,7 @@ func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
 	}
 
 	b.WriteByte('\n')
-	return b.Bytes(), nil
+	return b.Bytes()[1:], nil
 }
 
 func printColored(b *bytes.Buffer, entry *Entry, keys []string) {

text_formatter_test.go

@@ -31,3 +31,30 @@ func TestQuoting(t *testing.T) {
 	checkQuoting(false, errors.New("invalid"))
 	checkQuoting(true, errors.New("invalid argument"))
 }
+
+func TestTextPrint(t *testing.T) {
+	tf := &TextFormatter{DisableColors: true}
+	byts, _ := tf.Format(&Entry{Message: "msg content"})
+
+	// make sure no leading or trailing spaces
+	if string(byts) !=
+		"time=\"0001-01-01T00:00:00Z\" level=panic msg=\"msg content\"\n" {
+		t.Errorf("not expected: %q", string(byts))
+	}
+}
+
+func TestColorPrint(t *testing.T) {
+	tf := &TextFormatter{ForceColors: true}
+	entry := WithField("testkey", "value")
+	entry.Message = "msg content"
+	byts, _ := tf.Format(entry)
+
+	// make sure no leading or trailing spaces
+	if string(byts) !=
+		"\x1b[31mPANI\x1b[0m[0000] " +
+			// length 44 plus one space
+			"msg content                                  " +
+			"\x1b[31mtestkey\x1b[0m=value\n" {
+		t.Errorf("not expected: %q", string(byts))
+	}
+}