Merge pull request #4 from apache/develop

common/extension/router_factory.go

common/extension/service_discovery.go

common/proxy/proxy.go

common/proxy/proxy_factory.go

common/proxy/proxy_factory/default.go

common/rpc_service.go

common/rpc_service_test.go

common/url.go

common/yaml/yaml.go

common/yaml/yaml_test.go

config/application_config.go

config/config_loader.go

config/config_loader_test.go

config/consumer_config.go

config/instance/metedata_report.go

config/interfaces/config_reader.go

config/metadata_report_config.go

config/metadata_report_config_test.go

config/provider_config.go

config/reference_config.go