Set up CI for running tests and generating a deployable version of th…

…e test application

* the generated artifact will only be uploaded if the action was started manually

.github/workflows/ci.yaml

@@ -0,0 +1,31 @@
+name: Java CI
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up JDK
+        uses: actions/setup-java@v2
+        with:
+          java-version: '8'
+          distribution: 'adopt'
+      - name: Build with Maven
+        run: mvn --batch-mode --update-snapshots verify
+
+      - name: 'Upload Artifact'
+        if: github.event_name == 'workflow_dispatch'
+        uses: actions/upload-artifact@v2
+        with:
+          name: csrfguard-latest-test-application
+          path: |
+            csrfguard-test/csrfguard-test-jsp/csrfguard-test-jsp-*SNAPSHOT.war
+            csrfguard-test/csrfguard-test-jsp/csrfguard-test-jsp-*SNAPSHOT-executable.jar
+          retention-days: 3