NIFI-6187

Added checkbox task for building on JDK 8 and JDK 11.
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 5cbcb1a..4bddb95 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -22,6 +22,7 @@
 ### For code changes:
 - [ ] Have you ensured that the full suite of tests is executed via `mvn -Pcontrib-check clean install` at the root `nifi` folder?
 - [ ] Have you written or updated unit tests to verify your changes?
+- [ ] Have you verified that the full build is successful on both JDK 8 and JDK 11?
 - [ ] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under [ASF 2.0](http://www.apache.org/legal/resolved.html#category-a)? 
 - [ ] If applicable, have you updated the `LICENSE` file, including the main `LICENSE` file under `nifi-assembly`?
 - [ ] If applicable, have you updated the `NOTICE` file, including the main `NOTICE` file found under `nifi-assembly`?