Merge pull request #4 from apache/develop

cluster/loadbalance/consistent_hash.go

cluster/router/condition/app_router_test.go

cluster/router/condition/file.go

cluster/router/condition/listenable_router.go

cluster/router/condition/router.go

cluster/router/condition/router_rule.go

cluster/router/condition/router_rule_test.go

cluster/router/router.go

cluster/router/tag/factory.go

cluster/router/tag/factory_test.go

cluster/router/tag/file.go

cluster/router/tag/file_test.go

cluster/router/tag/router_rule.go

cluster/router/tag/router_rule_test.go

cluster/router/tag/tag_router.go

cluster/router/tag/tag_router_test.go

common/constant/key.go

common/extension/auth.go

common/extension/metadata_report_factory.go

common/extension/registry_directory.go