Add test CI

Author: tadayosi

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: maven
+    directory: '/'
+    schedule:
+      interval: monthly

.github/workflows/test.yml

@@ -0,0 +1,33 @@
+name: Test
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths-ignore:
+      - "**.md"
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - "**.md"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        java: [ '17', '21' ]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Set up Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: ${{ matrix.java }}
+          cache: 'maven'
+      - name: Build & test
+        run: |
+          mvn --batch-mode --no-transfer-progress install