Modernize GH Action CI (#1812)

.github/workflows/maven.yml

@@ -19,26 +19,20 @@ jobs:
 
     steps:
 
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
 
     - name: Set up JDK ${{ matrix.java }}
-      uses: actions/setup-java@v1
+      uses: actions/setup-java@v2
       with:
         java-version: ${{ matrix.java }}
-
-    - name: Cache dependencies
-      uses: actions/cache@v1
-      with:
-        path: ~/.m2/repository
-        key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
-        restore-keys: |
-          ${{ runner.os }}-maven
+        distribution: 'temurin'
+        cache: 'maven'
 
     - name: Build with Maven
       run: mvn -Pjacoco clean verify -B -V --no-transfer-progress ${{ matrix.flags }}
 
     - name: Codecov coverage
-      uses: codecov/codecov-action@v1
+      uses: codecov/codecov-action@v2
       with:
         file: '*jacoco.xml'