Bump to upload-artifact@v2 (#3631)

Author: asciimike

content/actions/learn-github-actions/essential-features-of-github-actions.md

@@ -75,7 +75,7 @@ jobs:
         run: |
           expr 1 + 1 > output.log
       - name: Upload output file
-        uses: actions/upload-artifact@v1
+        uses: actions/upload-artifact@v2
         with:
           name: output-log-file
           path: output.log