Merge pull request #30 from mintdaniel42/master

Make Scheduler AutoClosable

src/main/java/com/coreoz/wisp/Scheduler.java

@@ -34,7 +34,7 @@
  * A job is executed only once at a time.
  * The scheduler will never execute the same job twice at a time.
  */
-public final class Scheduler {
+public final class Scheduler implements AutoCloseable {
 	private static final Logger logger = LoggerFactory.getLogger(Scheduler.class);
 
 	/**
@@ -516,4 +516,9 @@ private void runJob(Job jobToRun) {
 			scheduleNextExecution(jobToRun);
 		}
 	}
+
+	@Override
+	public void close() {
+		gracefullyShutdown();
+	}
 }