Merge pull request #168 from per1234/update-slack-notify-action

Use major version ref of action in workflow

Author: per1234

.github/workflows/check-certificates.yml

@@ -57,7 +57,7 @@ jobs:
       # See: https://github.com/rtCamp/action-slack-notify
       - name: Slack notification of certificate verification failure
         if: failure()
-        uses: rtCamp/action-slack-notify@v2.1.0
+        uses: rtCamp/action-slack-notify@v2
         env:
           SLACK_WEBHOOK: ${{ secrets.TEAM_TOOLING_CHANNEL_SLACK_WEBHOOK }}
           SLACK_MESSAGE: |
@@ -111,7 +111,7 @@ jobs:
       - name: Slack notification of pending certificate expiration
         # Don't send spurious expiration notification if verification fails
         if: failure() && steps.check-expiration.outcome == 'failure'
-        uses: rtCamp/action-slack-notify@v2.1.0
+        uses: rtCamp/action-slack-notify@v2
         env:
           SLACK_WEBHOOK: ${{ secrets.TEAM_TOOLING_CHANNEL_SLACK_WEBHOOK }}
           SLACK_MESSAGE: |