added cleanup steps to remove temp resources, etc.

dependency-check-gradle/src/main/groovy/com/tools/security/tasks/DependencyCheckTask.groovy

@@ -61,6 +61,8 @@ class DependencyCheckTask extends DefaultTask {
         analyzeDependencies(engine)
         retrieveVulnerabilities(engine)
         generateReport(engine)
+
+        cleanup(engine)
     }
 
     private Engine initializeEngine() {
@@ -73,6 +75,11 @@ class DependencyCheckTask extends DefaultTask {
         overrideCveUrlSetting()
     }
 
+    def cleanup(engine) {
+        Settings.cleanup(true)
+        engine.cleanup();
+    }
+
     def verifyDependencies(engine) {
         logger.lifecycle("Verifying dependencies for project ${currentProjectName}")
         getAllDependencies(project).each { engine.scan(it) }