Run parallel tests in CI (#198)

* Remove unused dependency references

* Run parallel tests in CI

The plugin includes several long running tests that benefit from using
at least one JVM per core on the test machine.

Jenkinsfile

@@ -1,7 +1,16 @@
 // Specify configurations explicitly to test against newer LTS.
 // See also https://github.com/jenkins-infra/pipeline-library/pull/145
 
-buildPlugin(useContainerAgent: true, configurations: [
-  [ platform: 'linux', jdk: '11' ],
-  [ platform: 'windows', jdk: '17' ],
-])
+buildPlugin(
+  // Run a JVM per core in tests
+  forkCount: '1C',
+  // Container agents start faster and are easier to administer
+  useContainerAgent: true,
+  // Show failures on all configurations
+  failFast: false,
+  // Test Java 11 and Java 17
+  configurations: [
+    [platform: 'linux',   jdk: '17'], // Linux first for coverage report on ci.jenkins.io
+    [platform: 'windows', jdk: '11'],
+  ]
+)

pom.xml

@@ -165,17 +165,6 @@
           <scope>import</scope>
           <type>pom</type>
         </dependency>
-        <dependency>
-          <groupId>javax.annotation</groupId>
-          <artifactId>javax.annotation-api</artifactId>
-          <version>1.3.2</version>
-        </dependency>
-        <dependency>
-          <groupId>commons-net</groupId>
-          <artifactId>commons-net</artifactId>
-          <version>3.9.0</version>
-          <scope>test</scope>
-        </dependency>
       </dependencies>
     </dependencyManagement>