Update release.yml (#74)

Include the requirement for a reviewer to approve the release before initiating the release pipeline and deploying the image to Docker Hub.

.github/workflows/release.yml

@@ -7,6 +7,7 @@ on:
 jobs:
   docker:
     name: Release Docker
+    environment: release
     runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory