Use root6.20.04 release tag

significantly smaller

Author: matthewfeickert

.github/workflows/ci.yml

@@ -53,7 +53,7 @@ jobs:
   test-ROOT-6_20-Py-3_7:
 
     runs-on: ubuntu-latest
-    container: pyhf/pyhf-validation-root-base:root6.20.00-python3.7
+    container: pyhf/pyhf-validation-root-base:root6.20.04-python3.7
 
     steps:
     - uses: actions/checkout@master

.github/workflows/publish.yml

@@ -22,7 +22,7 @@ jobs:
         password: ${{ secrets.DOCKER_PASSWORD }}
         repository: pyhf/pyhf-validation
         dockerfile: docker/Dockerfile
-        tags: latest,root6.20.00,root6.20.00-python3.7
+        tags: latest,root6.20.04,root6.20.04-python3.7
     - name: Build and Publish to Registry with Release Tag
       if: startsWith(github.ref, 'refs/tags/')
       uses: docker/build-push-action@v1
@@ -31,5 +31,5 @@ jobs:
         password: ${{ secrets.DOCKER_PASSWORD }}
         repository: pyhf/pyhf-validation
         dockerfile: docker/Dockerfile
-        tags: latest,latest-stable,root6.20.00,root6.20.00-python3.7
+        tags: latest,latest-stable,root6.20.04,root6.20.04-python3.7
         tag_with_ref: true

docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM pyhf/pyhf-validation-root-base:root6.20.00-python3.7 as base
+FROM pyhf/pyhf-validation-root-base:root6.20.04-python3.7 as base
 
 FROM base as builder
 COPY . /code