More CI changes

.github/workflows/checkstyle.yml

@@ -0,0 +1,15 @@
+name: Check PR Codestyle
+on: [ pull_request ]
+
+jobs:
+  checkstyle:
+    name: Checkstyle
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dbelyaev/action-checkstyle@v0.5.1
+        with:
+          github_token: ${{ secrets.github_token }}
+          reporter: github-pr-review
+          level: warning
+          checkstyle_config: ../../config/checkstyle/checkstyle.xml

.github/workflows/java-ci.yml

@@ -1,6 +1,6 @@
 name: Java CI
 
-on: [push]
+on: [ push, pull_request ]
 
 jobs:
   build:

.github/workflows/test-publish.yml

@@ -1,6 +1,6 @@
 name: Publish API (Dev)
 
-on: [ push ]
+on: [ push, pull_request ]
 
 jobs:
   publish-release: