Run tests also with Java 12

Minimum runtime Java 7
diff --git a/Jenkinsfile b/Jenkinsfile
index 09ac70f..b21831c 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -17,4 +17,4 @@
  * under the License.
  */
 
-asfMavenTlpStdBuild()
+asfMavenTlpStdBuild(jdks:['7','8','11','12'])
diff --git a/src/test/java/org/apache/maven/shared/dependency/analyzer/DefaultProjectDependencyAnalyzerTest.java b/src/test/java/org/apache/maven/shared/dependency/analyzer/DefaultProjectDependencyAnalyzerTest.java
index 84b0d48..09fc24c 100644
--- a/src/test/java/org/apache/maven/shared/dependency/analyzer/DefaultProjectDependencyAnalyzerTest.java
+++ b/src/test/java/org/apache/maven/shared/dependency/analyzer/DefaultProjectDependencyAnalyzerTest.java
@@ -341,8 +341,8 @@
         if ( SystemUtils.isJavaVersionAtLeast( JavaVersion.JAVA_9 )
              && !properties.containsKey( "maven.compiler.source" ) )
         {
-          properties.put( "maven.compiler.source", "1.6" );
-          properties.put( "maven.compiler.target", "1.6" );
+          properties.put( "maven.compiler.source", "1.7" );
+          properties.put( "maven.compiler.target", "1.7" );
         }
         
         String httpsProtocols = System.getProperty( "https.protocols" );