update discovery for kubernetes, requires go 1.11+

CMakeModules/testing_go.cmake

asapo_tools/CMakeLists.txt

authorizer/CMakeLists.txt

broker/CMakeLists.txt

...y/asapo_helm_chart/asapo/templates/broker-deployment.yaml

discovery/CMakeLists.txt

discovery/src/asapo_discovery/common/structs.go

discovery/src/asapo_discovery/go.sum

discovery/src/asapo_discovery/main/discovery.go

...asapo_discovery/request_handler/request_handler_consul.go

...o_discovery/request_handler/request_handler_kubernetes.go

...covery/request_handler/request_handler_kubernetes_test.go

discovery/src/asapo_discovery/server/settings_test.go

file_transfer/CMakeLists.txt