Make build work with Java17 (#27)

In short: now build works on both, Java 11 and Java 17 (tested with 11 and 17 Temurin on Linux).

Similar to #61 and similarly, once this merged removal of Tycho is pending.

Changes:
* update GH workflow to use mvnw (instead of implicitly provided mvn by setup-java)
* update wrapper to 3.2.0 and Maven to 3.9.1
* update all build plugins to their latest versions

.github/workflows/build.yml

@@ -13,18 +13,19 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
+        java: [ '11', '17' ]
       fail-fast: false
 
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions/setup-java@v2
         with:
-          java-version: 11
+          java-version: ${{ matrix.java }}
           distribution: 'temurin'
           cache: 'maven'
 
       - name: Build with Maven
-        run: mvn verify -e -B -V
+        run: ./mvnw verify -e -B -V
 

.mvn/wrapper/maven-wrapper.properties

@@ -1,2 +1,18 @@
-distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.5/apache-maven-3.8.5-bin.zip
-wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.8/apache-maven-3.8.8-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar

CONTRIBUTING.md

@@ -27,7 +27,7 @@ Contact us
 Build
 -----
 
-The Sisu build requires Java 11 and Maven 3.6.3, while the resulting jars work with Java 1.7 and above.
+The Sisu build requires Java 11 and Maven 3.6.3 (or higher), while the resulting jars work with Java 8 and above.
 
 Coding Style
 ------------