Skip duplicate workflow runs

Author: dolfinus

.github/workflows/test.yml

@@ -7,9 +7,26 @@ on:
     - master
 
 jobs:
+  check_duplicate_runs:
+    name: Check for duplicate runs
+    continue-on-error: true
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@master
+        with:
+          concurrent_skipping: always
+          cancel_others: true
+          skip_after_successful_duplicate: false
+          paths_ignore: '["**/README.md", "**/LICENSE"]'
+          do_not_skip: '["pull_request"]'
+
   tests:
     name: Run tests
     runs-on: ubuntu-18.04
+    needs: [check_duplicate_runs]
     strategy:
       matrix:
         python-version: ['2.7', '3.3', '3.4', '3.5', '3.6', '3.7', '3.8', '3.9']