Include:
1. plugin/forward/type.go:8:2: const typeUdp should be typeUDP
2. plugin/forward/type.go:9:2: const typeTcp should be typeTCP
3. plugin/forward/type.go:10:2: const typeTls should be typeTLS
4. plugin/kubernetes/metrics.go:24:2: var DnsProgrammingLatency should be DNSProgrammingLatency
5. plugin/kubernetes/metrics_test.go:124:102: func parameter clusterIp should be clusterIP
Signed-off-by: zouyu <zouy.fnst@cn.fujitsu.com>