Add args to annotate

Make the compiler happy!

```
pkg/collector/collector.go:36: cannot use namespace.New(c.client, r.Name()) (type *namespace.Client) as type statsd.Client in argument to r.Start:
	*namespace.Client does not implement statsd.Client (wrong type for Annotate method)
		have Annotate(string, string) error
		want Annotate(string, string, ...interface {}) error
```