feat(gateway): refactored api-gateway-server to gateway-service in Dockerfile.confd
feat(gateway): refactored api-gateway-server to gateway-service in Dockerfile.confd

looztra/guestbook-api-server,looztra/guestbook-api-server,looztra/guestbook-api-server,looztra/guestbook-api-server,looztra/guestbook-api-server