Adding redis container and fixing release tagging

Author: Shillaker

.github/workflows/release.yml

@@ -33,3 +33,4 @@ jobs:
           push: true
           context: .
           tags: faasm/cpython:${{ env.TAG_VERSION }}
+          build-args: FAASM_CPYTHON_VERSION=${{ env.TAG_VERSION }}

.github/workflows/tests.yml

@@ -36,6 +36,9 @@ jobs:
     defaults:
       run:
         working-directory: /code/faasm-cpython
+    services:
+      redis:
+        image: redis
     steps:
       - name: "Fetch ref"
         run: git fetch origin ${GITHUB_REF}:ci-branch