only add a space between text entries if there is already content

So we don't have a trailing space at the end of each log line

text_formatter.go

@@ -154,11 +154,12 @@ func (f *TextFormatter) needsQuoting(text string) bool {
 }
 
 func (f *TextFormatter) appendKeyValue(b *bytes.Buffer, key string, value interface{}) {
-
+	if b.String() != "" {
+		b.WriteByte(' ')
+	}
 	b.WriteString(key)
 	b.WriteByte('=')
 	f.appendValue(b, value)
-	b.WriteByte(' ')
 }
 
 func (f *TextFormatter) appendValue(b *bytes.Buffer, value interface{}) {

text_formatter_test.go

@@ -16,7 +16,7 @@ func TestFormatting(t *testing.T) {
 		value    string
 		expected string
 	}{
-		{`foo`, "time=\"0001-01-01T00:00:00Z\" level=panic test=foo \n"},
+		{`foo`, "time=\"0001-01-01T00:00:00Z\" level=panic test=foo\n"},
 	}
 
 	for _, tc := range testCases {