Add redis cache to postgres testcase

.github/workflows/postgresql.yaml

@@ -27,6 +27,7 @@ jobs:
       INVENTREE_DEBUG: info
       INVENTREE_MEDIA_ROOT: ./media
       INVENTREE_STATIC_ROOT: ./static
+      INVENTREE_CACHE_HOST: localhost
 
     services:
       postgres:
@@ -37,6 +38,11 @@ jobs:
         ports:
           - 5432:5432
 
+      redis:
+        image: redis
+        ports:
+          - 6379:6379
+
     steps:
       - name: Checkout Code
         uses: actions/checkout@v2

InvenTree/InvenTree/settings.py

@@ -541,7 +541,9 @@ DATABASES = {
 
 _cache_config = CONFIG.get("cache", {})
 _cache_host = _cache_config.get("host", os.getenv("INVENTREE_CACHE_HOST"))
-_cache_port = _cache_config.get("port", os.getenv("INVENTREE_CACHE_PORT"))
+_cache_port = _cache_config.get(
+    "port", os.getenv("INVENTREE_CACHE_PORT", "6379")
+)
 
 if _cache_host:
     # We are going to rely upon a possibly non-localhost for our cache,