Add on_retry_command input to optionally run cmd before a retry (#33)

* minor: add on_retry_command input to optionally run cmd before a retry

* test: add test for on-retry-command failure

.github/workflows/ci_cd.yml

@@ -60,6 +60,26 @@ jobs:
           actual: ${{ steps.sad_path_wait_sec.outputs.exit_error }}
           comparison: contains
 
+      - name: on-retry-cmd
+        id: on-retry-cmd
+        uses: ./
+        continue-on-error: true
+        with:
+          timeout_minutes: 1
+          max_attempts: 3
+          command: node -e "process.exit(1)"
+          on_retry_command: node -e "console.log('this is a retry command')"
+
+      - name: on-retry-cmd (on-retry fails)
+        id: on-retry-cmd-fails
+        uses: ./
+        continue-on-error: true
+        with:
+          timeout_minutes: 1
+          max_attempts: 3
+          command: node -e "process.exit(1)"
+          on_retry_command: node -e "throw new Error('This is an on-retry command error')"
+
       - name: sad-path (error)
         id: sad_path_error
         uses: ./