update CI config for pull requests

see https://securitylab.github.com/research/github-actions-preventing-pwn-requests/

.github/workflows/pullrequest.yml

@@ -0,0 +1,26 @@
+name: Pull Request
+
+on:
+  pull_request:
+
+env:
+  JAVA_VERSION: 17
+
+defaults:
+  run:
+    shell: bash
+
+jobs: 
+  test:
+    name: Compile and Test
+    runs-on: ubuntu-latest
+    if: "!contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]')"
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v2
+        with:
+          distribution: 'temurin'
+          java-version: ${{ env.JAVA_VERSION }}
+          cache: 'maven'
+      - name: Build and Test
+        run: mvn -B clean install jacoco:report -Pcoverage,dependency-check