Change name of release artifact and update Dockerfile to use artifact from previous step

.gitlab-ci.yml

@@ -44,7 +44,7 @@ build:
     - deps
   image: golang:1.12
   script:
-    - GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -mod=readonly -o release/k8s-go -ldflags '-w -s'
+    - GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -mod=readonly -o release/default-request-adder -ldflags '-w -s'
   artifacts:
     paths:
       - release/