Try notifying Slack from Actions

https://github.com/8398a7/action-slack
https://github.com/marketplace/actions/action-slack

.github/workflows/macos.yml

@@ -58,3 +58,15 @@ jobs:
         if: matrix.test_task != 'check'
       - name: Leaked Globals
         run: make -s leaked-globals
+      - uses: 8398a7/action-slack@v1
+        with:
+          type: success
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: success()
+      - uses: 8398a7/action-slack@v1
+        with:
+          type: failure
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure()

.github/workflows/ubuntu.yml

@@ -58,3 +58,15 @@ jobs:
         continue-on-error: true
       - name: Leaked Globals
         run: make -s leaked-globals
+      - uses: 8398a7/action-slack@v1
+        with:
+          type: success
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: success()
+      - uses: 8398a7/action-slack@v1
+        with:
+          type: failure
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure()

.github/workflows/windows.yml

@@ -53,3 +53,15 @@ jobs:
         run: |
           call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
           nmake ${{ matrix.test_task }}
+      - uses: 8398a7/action-slack@v1
+        with:
+          type: success
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: success()
+      - uses: 8398a7/action-slack@v1
+        with:
+          type: failure
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure()