Test builds before release step runs

Author: emily-curry

.github/workflows/release-tests.yaml

@@ -4,11 +4,7 @@ on:
   pull_request:
     branches:
       - master
-      - releases/*
-  push:
-    branches:
-      - master
-      - releases/*
+  workflow_call:
 
 jobs:
   build:

.github/workflows/release.yaml

@@ -13,8 +13,13 @@ on:
           - "major"
 
 jobs:
+  # snapshot build of every release target, including the multi-platform docker
+  # images, so a broken build fails before we tag and publish anything
+  release-tests:
+    uses: ./.github/workflows/release-tests.yaml
   publish:
     name: publish - ${{ inputs.type }}
+    needs: release-tests
     runs-on: ubuntu-latest-16-core
     environment: "production"
     permissions: