fixes on rolloutController#create, dockerfile, and swagger

- update golang version in dockerfile

- rollout#create returns empty id,

- swagger-response for delete should be empty

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.14-alpine as build
+FROM golang:1.16.5-alpine as build
 EXPOSE 8080
 
 WORKDIR /src/

external/interface/httpintf/httpapi/ReleaseRolloutController.go

@@ -127,6 +127,7 @@ func (ctrl ReleaseRolloutController) Create(w http.ResponseWriter, r *http.Reque
 	}
 
 	var resp CreateReleaseRolloutResponse
+	resp.Body.Rollout.ID = p.Rollout.ID
 	resp.Body.Rollout.FlagID = p.Rollout.FlagID
 	resp.Body.Rollout.EnvironmentID = p.Rollout.DeploymentEnvironmentID
 	resp.Body.Rollout.Plan = release.RolloutDefinitionView{Definition: p.Rollout.Plan}
@@ -308,12 +309,6 @@ type DeleteReleaseRolloutRequest struct {
 // DeleteReleaseRolloutResponse
 // swagger:response deleteReleaseRolloutResponse
 type DeleteReleaseRolloutResponse struct {
-	// in: body
-	Body struct {
-		Rollout struct {
-			Plan interface{} `json:"plan"`
-		} `json:"rollout"`
-	}
 }
 
 /*

external/interface/httpintf/swagger/swagger.json

@@ -1044,22 +1044,7 @@
       "description": "DeleteReleasePilotResponse"
     },
     "deleteReleaseRolloutResponse": {
-      "description": "DeleteReleaseRolloutResponse",
-      "schema": {
-        "type": "object",
-        "properties": {
-          "rollout": {
-            "type": "object",
-            "properties": {
-              "plan": {
-                "type": "object",
-                "x-go-name": "Plan"
-              }
-            },
-            "x-go-name": "Rollout"
-          }
-        }
-      }
+      "description": "DeleteReleaseRolloutResponse"
     },
     "errorResponse": {
       "description": "ErrorResponse will contains a response about request that had some kind of problem.\nThe details will be included in the body.",