Refactor CI exclude

Author: Andrew-Chen-Wang

.github/workflows/test.yml

@@ -14,16 +14,47 @@ jobs:
         exclude:
           - python-version: '3.6'
             django: 'main'
+            memcache: 'pylibmc'
+          - python-version: '3.6'
+            django: 'main'
+            memcache: 'pymemcache'
+          - python-version: '3.6'
+            django: 'main'
+            memcache: 'python-memcached'
+          - python-version: '3.7'
+            django: 'main'
+            memcache: 'pylibmc'
           - python-version: '3.7'
             django: 'main'
-          - memcache: 'memcached'
-            django: '3.2'
-          - memcache: 'memcached'
+            memcache: 'pymemcache'
+          - python-version: '3.7'
             django: 'main'
+            memcache: 'python-memcached' 
+
+          - memcache: 'pymemcache'
+            django: '2.2'
+            python-version: '3.6'
           - memcache: 'pymemcache'
             django: '2.2'
+            python-version: '3.7'
+          - memcache: 'pymemcache'
+            django: '2.2'
+            python-version: '3.8'
+          - memcache: 'pymemcache'
+            django: '2.2'
+            python-version: '3.9'
+          - memcache: 'pymemcache'
+            django: '3.1'
+            python-version: '3.6'
+          - memcache: 'pymemcache'
+            django: '3.1'
+            python-version: '3.7'
+          - memcache: 'pymemcache'
+            django: '3.1'
+            python-version: '3.8'
           - memcache: 'pymemcache'
             django: '3.1'
+            python-version: '3.9'
 
     steps:
     - uses: actions/checkout@v2