Exclude 3.7 on ckan 2.8

Author: pdelboca

.github/workflows/test.yaml

@@ -45,8 +45,11 @@ jobs:
 
     strategy:
       matrix:
-        python-version: [ 2.7, 3.6, 3.7 ]
+        python-version: [ 2.7, 3.7 ]
         ckan-version: [ 2.8, 2.9 ]
+        exclude:
+          - python-version: 3.7
+            ckan-version: 2.8
     env:
       CKAN_PATH: ./ckan
       VIRTUAL_ENV: "1"  # let's fake a virtual environment, why not